Does anyone fancy attempting an antique-style nautical chart ? I'm running a D&D campaign for a group of folk just now which is based on this map:
Only in my version there's a sheer stone pinnacle in the centre of the whirlpool. In reality it contains a hidden prison tower for the BBEG and the whirlpool is like a magical barrier to keep it in / disturbances out, but that's not common knowledge. Since the BBEG has started rebuilding his powers, the whirlpool has got MUCH stronger in response to his escape attempts. Anyway, I digress.
What I'm looking for is a map of that central area that I can potentially turn into a puzzle. What I'm thinking of is giving the players something like 2-3 partial maps printed onto thin paper so that when they overlay them correctly, they'll reveal both the complete map and a coded message detailing where to find the the entrance to the BBEG's tower. The key to deciphering the code and some other stuff will be collected en route as they search for the map.
So what I'm looking for is a base map of those islands around the whirlpool with space for a couple of pirate-towns on the edges, so some of the outer islands should have natural harbours and a source of fresh water. They don't need to have a source of food or even much land necessarily (the 'towns' could simply be groups of ships / wrecks tied together) because the idea would be that normally they would only serve as temporary refuges for merchant ships travelling around the archipelago). The closer you get to the whirlpool, the harder it should be to navigate (so loads of submerged rocks, shipwrecks, islands close together and shallow shoals - stuff like that, but randomly drawn over the three maps so a 'safe' channel on one piece is revealed to be deadly when pieces 2&3 are added). The idea is that without the three(ish) pieces of map and the Tower Key, the players can't get to the BBEG. At least not easily.
I'll probably give this a go myself if no-one else is able or willing, but I'd love to see what you guys can come up with since it will undoubtedly be better

If you're able to provide the maps either as separate jpgs, or ideally as photoshop or gimp native files (with layers) that would be amazing. I'll add the riddles later.
We're playing in a 'standard' medieval fantasy setting using D&D 4e and it's relatively low-magic at the moment insofar as it exists in plenty of artefacts and plot-relevant devices, but actually being able to use it is a rare gift. Wizards are pretty rare beyond the occasional PC in the mortal realm and the other realms haven't started making much of an appearance yet.