This is a strange term. This probably relates to a small larva which is seen in the saltwater to sea, but there are really no "lice
" in seawater. In short nothing harmful that you get from the sea is still extant on the skin after you come out.
The exceptions here are bites you may have received while you were still in the water which show up in the skin, like man-of-war bites and other jellyfish.