I''ve never chartered, just lucky, I guess, so I would not know the level of equipment on board to expect. But my preventer is pretty straight forward. I use a line with a snap shackle with long trip lanyard that attaches to the mid-point of my boom, near where the hydraulic vang is attached. I then have a snatch block on the rail near the chainplates, perforated toerail makes it easy, I have no toerail, only track to the shrouds, so a padeye car is used. The tail is led back to the cockpit to an unused winch, usually one of my secondaries, near the reach of the helmsman. When a gybe is completed, the snatch block is moved to the new lee rail, and the preventer is snugged in.
When on a new boat for the first time, I always take a look around at the deck and rig. How long is the boom? Is it a "Deck Sweeper" when trimmed? Where are the "Safe Zones" that are out of harms way on deck.
My IOR design has a short 14'' boom. It uses end-boom sheeting. But being a race boat, when trimmed, the boom is of the "Deck Sweeper" variety, as in no one is safe during a gybe! I have a couple of lines marked on my deck going out to the rail from the traveler. When someone new is on the boat and not familiar with the subtleties of getting their head "softened", I tell them that the best place is behind the lines.
Heck, as an IOR design, I need as much afterguard in the stern when running as I can get.