How stupid is this idea?

In summer swimming across a strait(30km) on an air mattress, when water is very warm, on a day with 0 wind and with waters as calm as possible, where currents are weak. How likely is it to be able to do it? Ofc with lifejackets and sunscreen. that strait is not busy


What strait...Gibraltar, English Channel,Bosphorous, Danish/Swedish,Suez,Mallacca,these are all very busy shipping lanes and younwill most likely be crushed and chopped up by boat screws