I have long been puzzled by the widespread belief that if nature calls while swimming in the sea, one should dash ashore in search of a lavatory (Summer etiquette: 47 essential rules – from sex to sunloungers to shopping in swimming trunks, 14 July). Why this is considered the more virtuous option escapes me. The contents of the lavatory are, after all, treated and eventually discharged into rivers and seas. The ocean merely cuts out the middleman.

Assuming one is well away from other bathers, the environmental distinction seems elusive. The Atlantic Ocean has the capacity to cope with a few hundred millilitres of highly diluted human urine. It has been dealing with whales for rather longer than it has with us.

The morally superior toilet flush requires several litres of drinkable water to dispose of something that the sea has been recycling since life first crawled out of it.

Perhaps our discomfort is not with the act itself, but with imagining it. As so often, etiquette proves less a matter of science than of psychology.
Andreas Swadlo
Great Cheverell, Wiltshire

Some of my happiest memories are of swimming in the sea off the Connemara coast, on deserted beaches, the nearest public lavatory several miles away, and the next landfall to the west somewhere in Newfoundland. For the king’s former butler to tell me that I should not have had a pee is absurd. Never did the expression “a drop in the ocean” seem more apposite.
Andrew Wardrop
London

Is it OK to pee in the sea? The ultimate guide to summer etiquette concludes that it is not. “Go to the nearest lavatory.” This is surely to enable a privatised water company to do it for you.
Tony Coghan
London