Tag Archives: How To

HOW TO Articles Index

During the summer of 2013 I indexed all the cold and cold water swimming How Tos for your easy perusal. This time I am indexing the HowTo articles, each again getting a brief description.

HOWTO be an open water swimmer… One of the first posts on loneswimmer.com

HOWTO: Open water swim tips for beginners open water swimmers and triathletes.

HOWTO: Lane swimming etiquette. Essential conduct for all pool swimmers.

HOWTO: Marathon and Channel Swimming Swimmer and Crew Checklist (updated for 2013). Occasionally updated check-list for swimmer and crew.

HOWTO: Generic marathon swim Observer’s Report.

Improving triathlon swimming performance – Part 1. Addressing technique problems for triathletes.

Improving triathlon swimming performance – Part 2. Continued.

HOWTO: Swimming Notation. How to read common swimming training plan notation.

Sea Lice, Seabather’s Eruption and Swimmer’s Itch. Understanding and treating the various conditions

HOWTO: “How much do I need to swim for – x – open water distance?”. Various considerations in training for swimming a range of distances.

HOWTO: Progressive Step Overload training for distance swimmers and endurance athletes.

HOWTO: Discussing Zone Training. What is heart zone training and how it applies to swimming.

HOWTO Introduction to writing a basic pool swimming set. Writing a basic pool training plan for a single day.

HOWTO: Using Tide Tables. Using both online and printed Tide Tables for tide prediction and safety.

HOWTO: Tides for Swimmers, part 1 – Theory. It’s important that swimmers understand tidal aspects fully, especially those who live in high tidal range areas like Western Europe.

HOWTO: Tides For Swimmers, Part 2 – Local Effects. When considering tides, theory and local effects are often very different.

HOWTO: Understanding Waves, for Swimmers, Part 1. Waves, i.e. breakers are a difficulty for triathletes and new swimmers. Also important for coastal safety.

HOWTO: Understanding Waves, for Swimmers, Part 2.

HOWTO: Preparing for Cold Water. Basic cold water swimming introduction.

HOWTO: Annual advice for a Christmas or New Year’s swim in cold water for the irregular open water swimmer. An annual and very popular post. Longer than the previous post above.

HOWTO apply lubrication for distance sea swimming. Not everyone naturally knows how to do this.

HOWTO: Understanding Rough Water: Force Three. Specifics of a marginal sea condition.

HOWTO understand Sea Area Forecasts / Shipping News. Weather forecasting is a useful skill for distance swimmers.

HOWTO: Beaufort Wind Scale – An essential observational skill for the OW Swimmer. Being able to read wind conditions is essential to understanding the sea and safety.

HOWTOStudying weather online during a Force 10/11 blow. How to use online resources to track a storm and what various aspects mean.

HOWTO: Open water breathing patterns. The sea changes every day. To be an experienced sea swimmer you need to be able to adapt your breathing.

HOWTO: Swimming in rough water. Linked to the previous article.

HOWTO: Sample marathon swim feed schedule (MIMS). Feed schedules are personal, but this will give you an idea if you don’t know where to start.

HOWTO: Important factors in marathon swim feeding. Other factors outside the actual schedule for long distance feeding.

HOWTO: Introducing interval training to your swimming. Basics of swim training.

HOWTO: Understanding hypothermia in swimmers – Mild Hypothermia. Mild hypo is very common. How to recognise it (and not worry).

HOWTO: Understanding hypothermia in swimmers – Moderate & Severe Hypothermia. Moderate hypothermia is not moderate. Severe is life-threatening.

HOWTO: Diagnosing and addressing Moderate Hypothermia in swimmers. What to actually do about hypothermia.

HOWTO: Core Exercises, Part 1. Core exercise are recommended for swimmers to assist balance and strength and endurance.

HOWTO: Core Exercises, Part 2.

HOW TO: Why you SHOULD shower before you use the pool and why you SHOULDN’T pee in the pool. Things you need to know about pool hygiene.

HOWTO: One Simple Effective Core Exercise. One simple core exercise.

HOWTO: Theraband work for shoulder strengthening. Theraband work helps to prevent swimmer’s shoulder (impingement) problems.

HOWTO: Tennis Balls And Tights. A useful remediation technique for muscle knots that develop through training.

HOWTO: A simple open water swimmer’s first aid & medical kit. Be prepared, accidents happen around the sea.

HOWTO: Stretching for swimming. Help to avoid or reduce swimming injuries. Post-swim only.

HOWTO reduce a swimmer’s use of towels. Really. Not everything has to be complicated.

HOWTO make your swimsuit (swimming togs) last longer. Surprisingly, not every swimmer knows this simple tip.

HOWTO tie men’s swimming briefs. Another of the simple tips.

HOWTO get water out of your ear. A very popular search item leading into this site.

HOWTO: Jellyfish ID charts. Particularly for swimmers in Ireland and the UK.

St Patrick’s Day swimming nutrition. Not really. How to make a great Irish Coffee. How to make a great one!

HOWTO: Follow an English Channel swim online.

HOWTO: Write a basic daily swimming session.

Future How To articles will be added to this index, as I remember to so do!

How To: Improving triathlon swimming performance – Part 1

This post is one of a combined series of triathlon swim articles with Evan Morrison. Evan is a top American open water and marathon swimmer who holds several long distance records including Santa Barbara and the Ederle marathon swims.  His article considers some common mistakes people make while pool swim training (not technique errors) and how to improve. (We are also the co-founders and administrators of marathonswimmers.org). Evan also recently wrote  an excellent, easy-to-understand and follow simple front-crawl stroke tip.

While I written quite a few open water How To’s that are useful for both triathletes and open water novices, I thought some observations on the most common triathlete stroke problems that I’ve seen wouldn’t go astray and simple correction for these problems. 

Stroke Analysis

While all of these issues are visible to a good coach, many triathletes, (like myself as a swimmer), don’t have a local swim squad, regular coach or other swimmers to observe, intervene, or even to casually analyse their strokes. Swimming is the most technically difficult discipline in a triathlon. Quite unlike running or cycling, simply swimming more won’t necessarily improve your technique, and may even embed stroke errors more deeply. Fitness alone also isn’t sufficient. Swimming is a two-person sport in that it requires someone else to see what you are doing. So the best first tip is to get some stroke analysis. this doesn’t have to be complicated or expensive. You can ask at your pool or if you see someone whom is a good swimmer, I can pretty much guarantee that they’d be happy to help as almost all experienced swimmers understand this requirement. (Just ask when they between sets).

I know a triathlete who has been swimming for twenty years. That should make him an excellent swimmer. But because he not only doesn’t ask for input, but refuses any he is offered by anyone, his swimming hasn’t progressed or improved in any way in all that time. (And he also makes most to of the errors that Evan points out).


The most common question or complaint from novice swimmers refers to breathing. It is  often in the form of “I am very fit, I can run and cycle for miles, but I run out of air almost immediately when swimming“. You can have a sports car in the garage but if you don’t have fuel in the car it’s not going to go anywhere. In swimming the primary fuel isn’t food but oxygen. Stretching the car analogy, food is more like the lubricant used for an internal combustion engine, and air is more like the primary fuel. You need one to start and for power, and the other to keep the system working. So it is most important that you are continuously getting enough air by breathing. As all swimmers have favourite sayings they have heard from their coaches, one of mine that is relevant to this is you need to swim around your breathing, not breathe between your swimming. Many beginners seem to think of breathing as an addendum to swimming. The oldest and still most important instruction to swimmers is relax. Without being relaxed it’s difficult to breathe efficiently. A drill that helps this is the side kicking drill (below).

  • Don’t hold your breathe but exhale continuously underwater. Use both mouth and nose exhalation.
  • Don’t worry about speed, but take controlled strokes. (You can’t swim fast or efficiently without being able to swim slow).
  • To help control your breathing you can speak a word like “breathe” underwater on every arm-cycle, or even hum underwater.
  • Learn to exhale fully. Exhale and see if you sink. If you don’t try again, this time exhaling from lower in your abdomen and stomach. Pursing your lips adds exhalation pressure. (Easily demonstrated. Exhale as much as you can while reading this, then purse your lips and you will be able to exhale a little more).

Inflexible ankles

Inflexible ankles are common in triathletes who originally come from a running background or who emphasise running training. The repetitive impacts combined with a lack of focus on ankle flexibility leads to a decreased Range of Motion (ROM) in the ankles and leave some triathletes being unable to point their toes. In some cases not being able to point the foot at all, so the foot remains at up to 90 degrees to the lower leg. This adds significant drag, in effect a water-anchor to the swimmer. Stiff ankles will also cause the legs to drop down in the water, thereby adding yet more drag.

  • A simple solution to this is to increase ankle flexibility stretching. This has the great advantage of being amenable to being done while the person is sitting and relaxing or working. Two effective stretches from Michael Alter’s excellent Sport Stretches.

Ankle stretches 1-resized

Part 2.

HOW TO apply lubrication for distance sea swimming

I think I may have reached a new level of banality with this one. Or have I? Can I get more banal? After all, I’ve previously told you how to wash your swimsuit. And yet when ever I write a banal HowTo post, it ends up being useful to someone. Funnily enough, at MIMS this year someone said exactly that to me; “I’ve got to love a blog that tells you how to wash your swim suit”.

So everything is useful to someone. On my first ever visit to Dover, I think I’ve mentioned this previously, I recall getting changed under the shelter, (you Dover swimmer know the one, the one which actually provides no shelter because there’s no glass in it.) When a couple of guys came over and wanted to know what Danny Walsh and I were doing putting Vaseline under our armpits. It transpired that were there to do a Channel relay. I can understand we all have to learn, but try to do it before you get to Dover… and to that end…

I’ve covered the different types of grease generally previously (there were a couple missing from the list, emulsifying cream and something called Aquaphor). I’m sure where grease or lubrication is involved, people are inventive when faced with an immediate lack thereof coupled with a desire to swim. :-)

Let’s recap quickly though. For long distance swims people primarily choose petroleum jelly, lanolin, Channel grease, or a silicon lubricant.

  • To mix Channel grease you can use anywhere from a 50/50 mix to 90/10 lanolin to petroleum jelly.

The two big problems with applying pure lanolin are the fact that it gets almost solid when cold, and that it leaves a huge mess. Warming the lanolin or mixing up Channel grease solves the first problem, but not the second. So before you do anything you need to make sure either your hands are covered, or that you can completely clean your hands afterwards. Disposable gloves are the simple solution. I myself prefer to carry a damp dish-washing liquid with me to wipe off my fingers afterwards. For a big swim, like a Channel swim, I think it’s best to have both ready. Having recently seen this, let me clarify the process of applying grease for a Channel swim:

  • If using pure lanolin, sit the tub on a car dashboard, in the sun or (closed) in warm water to soften it first.
  • Do NOT apply petroleum jelly first and then try to apply cold lanolin on top of it.
  • Mix your grease first then apply, or apply only one or the other.

So you’ve got your grease and your gloves. Where do you put it?

  • The primary location that causes the most problems is under the armpits because the salt build up quickly. Make sure to get down a couple of inches below the armpit and in front if it’s along swim. If you are unsure how much to add, more can’t do you any harm.
  • For many people (e.g. me) the neckline behind the head under the hairline is an area of particular difficulty, even on short swims.
  • For some, depending on whether you have a beard, stubble or are clean shaven, you may want to lube along the jawline AND on top of the shoulders where the jaw may rub.
  • Some areas are more of personal preference. For men and women for long swims, between the thighs may be area of concern. If you have a particularly narrow stroke and are likely to touch your face to your arm on full extension, then possibly some grease on the outside of your shoulder may help,
  • Similarly, you may like to do a  thigh-scrape with your your recovering thumb on every stroke, in which case some grease on the outside of your thigh may be useful.
  • For men, for a Channel-duration swim, I suggest putting grease under the edges of the swimsuit, and around your genitals.
  • A female friend reminds me that for women, nipples can also be a serious chaffing problem on long sea swims.
  • For women, the straps of swimsuits often cause huge problems for long swims, with many women swimmers having to do a lot of experimentation to find a suitable swimsuit. Application of lanolin to these areas is also required for marathon duration swims.

What other factors are important?

  • For fresh water swims of over 4 hours I apply lubrication just because of pure skin-on-skin friction.
  • Salinity varies by location. The English Channel at 5% salinity is 20% more saline than the 4% salinity south coast of Ireland. Allow for the difference if you come from a lower salinity location.
  • As well as using Channel grease to allow for colder weather, also allow for warmer weather. In warmer climes lubrication easily runs off the body prior to swimming, as happened to a lot of people before this year’s MIMS.

What can happen if you don’t apply sufficient swim lubrication? Here’s a picture of a well known and respected marathon swimmer who ran into some problems. I haven’t touched the colour of the healing skin on the shoulders. Also look at the chaffing on the neck. Chaffing of this level comes with a significant amount of pain and a slow recovery and almost certainly long-lasting scars.


This post is dedicated to English Channel Record Holder Trent Grimsey!

Extreme cold adaptation in humans, part 2

Brave swimmer (13 degree celsius)
Image by aryel_bc via Flickr

Let’s back up a bit. Waay back in fact, to some of my first posts, where I talked about Habituation and Acclimatization.

By the way, if I was writing those posts now, since my experience had changed again, I would have different figures. It’s good that I can still see progression from there, because for those of you whoare maybe further behind on the curve, or further ahead, we can all be assured that we are on the same relative learning curve.

For a quick recap, habituation is the learned process (for our purposes) of getting used to getting into cold water.

Habituation doesn’t necessarily mean you get better at it (though it is fairly inevitable). It just means you get more used to doing it (not quite semantic difference). So you know that it’s not really going to kill you, and the pain is transient, therefore you don’t have to fight yourself quite as much to go or to get in the water.

Acclimatisation is the process of becoming used to and better at, staying in cold water. Therefore they are two quite separate processes. (It’s not acclimation by the way, since it happens in the natural environment.)

One can also see back those posts I was asking “how can Thought affect your cooling rate?”, which is your ability in cold water. I obviously used a capitalised word to indicate directed mentation toward the specific end of extending time spent swimming.

Over the past year and half I’ve indicated all (I think) of the pertinent environmental and physiological contributors.

So let’s set most of those aside (weather, health, diet).

Swimmers call the process of getting better at cold water hardening. Here’s some experiental data from swimmers about the hardening process: You can lose it four to five times quicker than you gain it. Sorry to start at the end but it’s because we can at least quantify it a bit better.

Going back to the start though, and what I tell people who ask me, is that you see a definite improvement in your short-term in-water experience within about five swims, in any particular lower temperature range. So if you start at 12 C, you will see the improvement there, whereas someone who starts at 10C should see a similar improvement.

Some people I’ve talked to starting off, separate from the not-insignificant initial problem of just immersing the face, found it difficult to impossible to hold their face in the water for more than four or five minutes, in what I would consider warmish water (12C). Others found pain in the hands and/or feet to be the issues, some find the desperate gasping for air to be the worst aspect. Some have many or all of these symptoms to varying degrees.

In fact, writing it all down like that makes you wonder why on earth we would ever voluntarily subject ourselves to it?

Also, a reminder, don’t look at someone heavier and assume it’s easier for them, a common mistake. A heavier person has greater volume so retains heat longer, but the initial pain will be just as intense.

So, we levelled the field and we’re back to the initial question: take me and someone else approximately similar measurements, standing on the Guillamenes platform in mid February about to get into the water. And assuming I have more experience I will be out later. Why?

I had not planned to leave you hanging here, it just turns out that as I write this, in this format, it is taking more than I initially realised, that I can pull in others factors to do a more comprehensive essay on the subject.

world tidal constituent

HOW TO: Tides For Swimmers, Part 2 – Local Effects

Part 1 – Theory

So, why a different post for what we can call the observed local effects?

Well, depending where you are in the world, this may not be needed. There are some places where the observed local effects match those predicted by theory.

However, why isn’t that the case for everywhere?

Simply, the oceans aren’t uniformly shaped basins. They have obviously irregularly shaped coasts, and differing sizes and depths, all of which interfere with the tidal wave. Gravitational effects (lunar and solar) cause waves. But inertia and drag also interfere with the tides.

This is a map of global tides. We need to look at the Global situation to understand the local situation.

world tidal constituent

Whoa there.

Okay, how about this simpler-to-read one?

global tides

All right, that second one’s a bit easier to read. Forget everything else and have a look at the Atlantic. Notice there is a node, a black point, in the centre of the North Atlantic, south of Greenland, east of Newfoundland, from which lines radiate out?

That’s the Atlantic Amphidromic Point.

This means it’s the point in the Atlantic where the tidal range is zero, i.e. it has no tide, it’s all at the same tide height. The tides radiate out and away from that.

The further you go the greater the tidal range.

Each of those lines reaching indicate different tide heights. The further away from the amphidromic point the greater the tide height. Each of those lines also has a number associated which is the (very) approximate tide range.

Now go back to the coloured chart. See how one you get up to Europe the tidal range (colour) gets higher (a deeper colour)? Compare the difference between California (and the Catalina Channel) and the Atlantic Isles and the English Channel.

Now lets back up again. Imagine the Atlantic is a rectangular basin. You pick it up sloosh the water from on side to another. Assuming you are not spilling it out, and keep it moving, there’s a point somewhere toward the middle where the water is hardly moving up and down, just backwards and forwards. The water at the ends though will pile up against the basin for the “high tide”.

Now also think of the moving water. All the water doesn’t move at the same time and most of the water from either side will never get to the other side. So this affects the locality of the tide even within the basin.

Now imagine swishing the water and trying to add a circular motion. It gets more complicated.

This also then applies on a global scale. The tidal wave doesn’t all go from A to Z and back to Z every 12 hours. A to Z is a long way with lots of intermediate points. So lets the water from A goes to C, the water from B goes to D etc. Or better yet. The water from Kerry makes it to West Cork, the water from West Cork makes it to Cork, the water from Cork makes it to Youghal etc. So that means each area’s tide is at a different time, as you already know.

So that’s the whole Atlantic situation: Here’s an animation of the simple and complex (real) models.

Imagine this applying to Ireland. Think of that tide coming towards Ireland. It’s coming from west. So imagine it arriving as a single wavefront. Some flowing into the west coast, some flowing up around Donegal, across the north coast, some flowing across the south coast, around Carnsore Point and up the east coast.

Ok, the tide wave doesn’t cover all the area. As said previously it’s actually water moving back and away from the originating point. And then what? See it?

Ireland is an island, with water flowing around it. Logically that flow must reach around the coast and each flow start to interfere with other. Which is does. There’s actually an amphidromic point north of Ireland near Skye, and in the Irish Sea just south of the Isle of Man and yet Lancashire and Cumbria, on the NE coast of England, not that far away, have the highest tides at eight metres and Carnsore in Wexford, is just 1.75 metres. According to the Irish Cruising Club, there is an amphidromic point close to the east coast 25 miles north of Carnsore.

But we’re not finished. So you’ve heard of Capes, Cape Horn etc. Ok you channel swimmers, your favourite, Cap de Griz. Well in geographical terms, a Cape is a headland that significantly affects the ocean currents around it.

It does this, and also other headlands to a lesser extent, by essentially forcing the tide to flow through a smaller opening like putting you finger over the end of a tap. (Hello Channel tides!) Or maybe the coast “falls away” froma tide flow, having the opposite effect.

And then there’s the estuarine effect where a tide flowing into a estuary gets higher as it is forced further in. The tide here outside my door is about 7 metres, 20 miles from the sea, where is about 5m normally.

The Irish Sea, because of the narrow North Channel, also acts as estuary, forcing higher tides further north along it. In fact there are really varying effects in the Irish Sea.

Courtown for example sometimes has 5 tides instead of 4, with a tiny variation between them. The tides around Kilmore Quay also can be 8 knots. Some other places have similar very strong tides, while a few miles away there are negligible tides.

So lots of effects. In the case of the south coast of Ireland, the only bit I feel qualified and experienced enough to talk about, all this combines to produce a “lag” effect, where the slack portion of the tide is NOT necessarily at the high and low water marks, as we saw is the theoretical case in the first post. Instead, depending where along the coast you can be, slack water may be the middle of the tide or other times.

The charts to determine this are published by the South West Cruising club and printed every year in Reed’s Almanac, the yearly sailing almanac, so I can’t really post them here. PM me if you want them and i’ll send them on, though they are a bit complicated apparently first time you see them.

All of which serves to demonstrate that adhering, as so many swimmers do, to a theoretical tide idea should be tempered with acknowledging that it’s necessarily the truth.

For good tide knowledge, sailors and kayakers are the best. Like us they are at the mercy of tides, but are further out so their knowledge is often more extensive and their literature is far more developed.

HOW TO: Tides for Swimmers, part 1 – Theory

One occasional bee I have in my swimming bonnet is the lack of understanding of tides amongst many OW swimmers. It is however quite understandable, if the location where you swim isn’t particularly affected by tides.

But what about expedition swim planning or trips to spots you don’t know? Or from a safety point of view planning a new participation swim? Or if like me you are prone to going solo. It’s good for swimmers to understand these factors.

In Dover, I spent an hour explaining tides generally, and how they affect the Channel, to two Italian relay swimmers, Martino and Michale (The first ever successful Italian relay team). In their case they swim in the Mediterranean, which is not very tidal, as any of you have been there will know. And they had no clue about tides. And it reminded me I was going to do some stuff here on tides months ago.

So we better start with the theory (don’t worry, it’s easy). Because some people who do know something about tides repeat the theory only, to the exclusion of local effects, or just don’t believe there are local effects. I learned this stuff when surfing and it was certainly my case when surfing, never realising that I was incorrect until I started swimming.

Ok. Whether you know it or not, tides are caused by the Moon AND the Sun. (A lot of people think it’s just the Moon), with the Moon being the main influence.

When the Sun, Earth and Moon are in a Direct Line, Spring tides are caused. (Pic 1. Spring Tides Diagram).

(These tides are called sub-lunar and antipodal).

(One of the biggest misunderstandings of non-coastal people is thinking Spring Tides happen in the Spring, instead of actually every two weeks).

In the case where you can’t see the Moon, that’s called a New Moon (another common misunderstanding) and the Moon is between the Sun and the Earth. Both gravitational forces, of the Sun and Moon, combine to pull the sea water away from the earth’s surface, the Spring Tides.
A Full Moon is when the Moon is on the opposite side of the Earth from the Sun, but the gravitational forces are still directly in-line.
Spring tides therefore happens approximately twice a month.

It’s “approximately” because the tide cycle follows the Lunar cycle and is around six and a quarter hours, meaning a Tide Period, one High and one Low tide, every twelve and a half hours. So you don’t have exactly four tides per day (24 hours), which is why you can’t go swimming on the same high tide every Saturday morning (or whenever) as the tides shift time gradually every day. Occasionally you get a second Full Moon within one calendar month, which is called a Blue Moon. (This is where the well known phrase originates.)

At the New Moon, the tides are called sub-lunar, while those on the other side of the world, away from the Moon’s closest influence are called antipodal, as the Moon’s gravitational effect is lessened and the Earth is pulled more than the ocean.

With Spring Tides, since the water is pulled MORE, that means the tides are both HIGHER and LOWER. The difference can be up to almost double the height. This is really important and I’ll come back to it at the end.

So the New Moon is the first Spring Tide. The second then occurs at the Full Moon. Full Moon is actually a Half Moon in lunar phase terms, that is, Second Quarter.

A Full Moon in NOT a New Moon!

So what about Neap tides?

Neaps also obviously then occur every other two weeks from the Springs. They happen when the Sun and Moon and Earth are at Quadrature, that is not directly aligned. This is around the First and Third Quarter periods of the Moon,.

The Sun and moon’s gravitational influence are acting in partial opposition (transverse) on the ocean, so the gravity pulling the water away from the surface is lessened. The Sun is pulling in one line and the Moon is pulling perpendicular to that direction.
(Pic 2 -Neap tides).

Ok. Got that?


Spring tides are higher and lower.
Neap’s and Spring’s cycle around each other with each occurring about twice a month.

Moving on… and back to the issue to tide height.

The single biggest misunderstanding of tides is just assuming that tides only go in and out, and therefore up and down. I think it’s a misunderstanding because again (non-coastal) people don’t pause to ask themselves what happens to all that water.

With tidal movement there is something called “The Rule of Twelfths”.

For this we average a tide into 6 hours.

In the first hour before AND after high (or low) tide, the tide will move one-twelfths of the total distance that it will move over the full 6 hour tide. So that’s 1 twelfth PLUS 1 twelfth equals 2 twelfths moved in two hours.

In the second tide before AND after high (or low) tide, the tide will move two-twelfths of the total distance that it will move over the full 6 hour tide. And that’s 2 twelfths PLUS 2 twelfth equals 4 twelfths moved in these two hours.

So for four of the six hours the die moves 2 twelfths plus 4 twelfths equals 6 twelfths which is only half the distance, in two-thirds of the time.

For the remaining 2 hours, which is the third and fourth hour of the tide, the tide moves three-twelfths in each hour, so it move the other half of the total distance in only one third of the time.

So…this means, that the tide is moving fastest in the central 2 hours of the tide.

Hour Distance (Speed)
1 1/12th
2 2/12ths
3 3/12ths
4 3/12ths
5 2/12ths
6 1/12th

So theory says: the tide is at it slackest, lowest or no movement, around high and low tides and the tide is moving at it’s quickest at mid tide. That speed is then directly related to whether it is Spring or Neap.

A Spring tide will have a greater range from higher to lower, so more water will move, so the speed of the running tide will be greater. A Spring High will be higher, a Spring Low will be lower.

For example a Spring Low will expose kelp at Tramore pier but a Neap Low Tide won’t.

In Ireland we have quite a big Tidal Range. Lowest Spring Tides are only 0.1 metres (above the Mean Datum of 0), while highest Spring Tides can be well over 6 metres. In the English Channel the highest is above 7 metres. The biggest tidal range in the world is 15 metres but the Mediterranean is only a metre or so!

So, almost there…with Spring Tides the two issues which you have to consider are:

  • Tidal Range. (Will it affect your ability to swim at a particular location, for example when it’s low tide, like at Sandycove?
  • Will the speed of the tide affect your ability to swim a particular distance in a particular time? (For example timing a swim across T-Bay or across the Waterford Estuary, or across the English Channel).


Recall: this is Theory. It will apply directly in some places, but not in other because of local effects. This is very important. I cannot tell you your local topography and geography.

Part 2.