In Britain, it means diddly. It means you're a male, presumably respectable. If you have no other title, then the overly-British will put esq. after your name on an envelope, etc. In America, I believe it's sometimes used after a lawyer's surname. However, I don't see it used much by U.S. lawyers.
Davit systems are most often used to lower an emergency lifeboat to the embarkation level to be boarded. Davits can also be used as man-overboard safety devices to retrieve personnel from the water. The lifeboat davit has falls (now made of wire, historically of manila rope) that are used to lower the lifeboat into the water.
Part 2: How do Dry Snorkels Work? Dry snorkels have a mechanism at the top of the tube that closes when you submerge under water. It also has a covering at the top to prevent surface water from splashing into the top of tube. The dry snorkel has a valve/hinge mechanism at the top. When you submerge underwater, accidentally or purposely, the hinge reacts via a float mechanism and closes onto the top of the tube and seals it which prevents water from filling the tube.