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.
The rocker arm is the link between the camshaft and the valves - functioning as a lever arm to multiply the cams lobe lift to the valve lift. Stock rocker arm ratios vary between manufacturers and engine types, but generally all small block Fords come with a 1.6:1 ratio rocker arm.