The Maelstrom system here in the UK has a downtime system that uses ships, in that your character can own a ship or several there of, each with certain amounts of cargo space etc that you can utilise for ferrying stuff around the world, between event locations (or even non-event locations) as a result of IC wheeling and dealing. It kinda removes them from the game in a way though, because it’s all purely an out-of-game thing, even down to the combat - in saying that it does add a very cool element to “downtime”. The snap in trying to emulate this is that about 50% of the MS system is actually “hidden” in that certain greater/heroic/epic advantages aren’t listed, and only become available to a player with a certain combination of other advantages - including those that pertain to ships, ship combat, and transferring cargo. This possibly draws some similarities with the Serenity system, which you could prod David H about.
A while back though I did have an idea for a LARP that would actually be run at two locations simultaneously, with some mode of transport passing to and fro. For my game it was likely going to be a panelvan with all the players locked in the back as if in the cargo hold of a train or similar, but you could probably modify it to replicate some form of travel via airship, the players catching the “ferry” from one destination to the other. As for not having one “on sight”, if you had a “zepplin station” with appropriate looking signage, the players should be able to fill in the blanks.
RE Bryn’s OOC system, it does sound very elegant but what about things like comparitive speed and manouverability? A lightly armed vessel might only have a short sword by comparison, but that warships’s cannons can’t fire in every direction and I bet it turns like a bitch. I bet you could actually generate a very simple (i can’t believe I’m suggesting this) turn based system that could be played out on a board in an OOC room, moderated by GMs if need be, that would be quick enough to avoid detracting from the game. Certain player skills could even have an impact, like if someone was an expert gunner, maybe the range of a ships weapons, damage they do, or even rate of fire are somehow augmented…
Umm, I have a couple of layouts in mind if you want me to pull them together and fling them your way. Something akin to Bookface’s “Battle Stations” meeting oldschool “Master of Orion 2”…