In between bouts of pounding away at my dissertation (fingers crossed I'll have it ready for defense in November), I've been curating my RPOL Chanbara game (three new players, maybe four) and working on filling in things in my old Maritime Campaign document.
You'd need to be a long-time WaHNtHaC... reader with an excellent memory to remember, as I was working on this, and ran two sessions of it before it collapsed, back in 2010.
"What is this?" I hear new readers and old readers without such excellent memories asking. Well, it was nine sheets of A4 maps of coastlines and archipelagos, and a few notes on running a massive oceanic sandbox game. I did the math. At 24 miles per hex, and 52 hexes top to bottom (portrait orientation), it stretches from arctic territory to tropics on an Earth-sized planet. Basically, the top 15 or 16 hexes on the top three maps are above the arctic circle, and bottom 15 or 16 hexes on the bottom three maps are below the northern tropic (fantasy world, so the tropics would have other names than Cancer and Capricorn).
There are coastlines (mainly peninsulas) on all the maps but the center one, obviously, and LOTS of islands, some big, some small.
The idea for it is to throw lots of rumors and quests at the players, but let them sail around exploring as they please in a Jason and the Argonauts style ship full of heroes. The Argonautica, the Odyssey, the voyages of Pytheas, Harryhausen Sindbad movies, actual Sindbad legends, The Voyage of the Dawn Treader, Pirates of the Caribbean movies, stories of Zheng He, Treasure Island, 20,000 Leagues Beneath the Sea, King Kong... All sorts of inspiration.
Back in 2010, I'd filled in some planned encounters on one of the maps only, plus I had some Random Encounter Tables (one of my old posts has them). That was about it. I had some vague ideas of teasing the players with an artifact quest, but leaving it up to them if they would bite or not.
Now, I've filled in information about each region on each of the maps -- culture/government/religion, languages, terrain types/climate. I'm working on random tables for determining what's on any particular island (or hex of larger islands, or mainlands) that makes it interesting (or not). I will also have a dozen or so planned encounters per map. All of the maps have some pirate/buccaneer, dragon, and "other big monsters" lairs marked on them. I need to also plan some artifact quests, lots and lots of rumors, inaccurate starting player maps, and a few other little things (like noting places other modules might fit in well), and I may have a marketable adventure module here.
A nautical sandbox. Wave Crawl? Seabox? Get on the ship and go to the place to do the things to get the things? I'm working on the catchy label for this type of adventure. And to make it more marketable, I'll probably either release it with dual stats (OSR/5E) or release two versions of it.