When we were in Dover two years ago for our two-way relay swim, one day we were getting ready to go swimming in the harbour. Three guys came over to us and we got talking, as is common in Dover. They had come from New York for a one-way relay.
They wanted to know why we were all rubbing “stuff” on our armpits. We were fairly surprised they didn’t know. Turned out they had never swam in salt water, only fresh or brackish, and were completely unaware of the issue of chafing that all affects all sea-swimmers.
The salt crystals will start to build up immediately between surfaces that are in contact, and after a short period will start to abrade the skin. If you don’t protect against it, it can break the skin, be really painful and take quite a while to heal.
For me I’m ok for about 15 minutes but any longer than that will require skin protection.
There’s a range of solutions.
Body-Glide is a rub-on stick designed with triathletes in mind. Easy to apply and I believe is good for up to an hour.
Petroleum Jelly is very common, easy enough to apply. Messy obviously. Lasts a few hours.
Lanolin is probably favourite for longer distance swimmers. It’s cheap but awfully messy to apply. (I carry toilet wipes to wipe off my fingers after, some apply it using plastic bags). It lasts a long time.
Channel grease is a mix of lanolin & petroleum jelly. Can be bought in Varne Ridge in Dover, apparently Boots Dover no longer supply it.
Be careful. You don’t want to get any of these on your goggles…
Runners World people visiting: I found the comment below in your discussion hilarious. I’ve never known a Channel swimmer say this. (And I know quite a few Channel & marathon swimmers). It’s even better when you notice the misspelling.
I know all the old channel swimmers used it. But…I spoke to a fellow long distance open water swimmer once who said lanolin is probably not the best substance to use for chaffing (not in salt water anyway). Not because it doesn’t work, but because it is a fatty oil derived from wool-bearing animals (i.e. it’s a protein). It’s been known to attack sharks.