Skin diver is a style that became popular in the 1950's with the rise in scuba diving as a hobby. They are usually slimmer than a conventional divers watch and have limited depth ratings.

One technology that progressed from skin divers were compressor watches, these used a case developed by E.S.P.A. As the wearer got deeper the pressure increased and forced the case tighter. As materials and manufacturing techniques inproved, compressor cases became unnecessary and although compressors are still available today, (Christopher Ward does one) Its mostly a style thing with duel crowns as in Dan Henry's 1970 diver.

I'm pretty much into diving watches but I've not seen this manufacturer before, definitely piqued my interest. Another to add to ever expanding wish list.