I had everything: Ship Maps, Naval Combat System, An Archipelago, Plot points. My party didn't like the idea of being "trapped in a boat" "Boats should be means to go somewhere, not the adventure" it was a matter of personal taste you know.
Here's what happened so far and what will happen.
The PCs sided with their captain during a mutiny and were left for dead stranded on the coast of the mainland after the first mate successfully killed the captain. They managed to gain a ship after winning the favor of a local noble, and set off after their old ship to seek revenge against the first mate.
Hearing rumors that the first mate has headed off towards an island chain with the goal of reviving the captain as a zombie, the crew has set sail.
On the way to the islands they encounter a crazy storm and end up stranded on an unmapped island.
This is where we are now.
The plan is for the island to be the lost capital of an ancient sea empire which was wiped out when the volcano on the island killed all the inhabitants, Pompeii style.
Knowledge of the island has been lost since the magical defense that sprung up when the volcano erupted have kept the island from being rediscovered and nobody has been alive on the island to turn off the magical defenses. The only reason our PCs end up on the island is due to the freak storm that basically whirlpools them through the defenses.
I'm planning a super dungeon here in the lost capital.
The capital city is a series of concentric rings with each layer being guarded by tougher and tougher enemies which will be described as being part of the magical defenses of the city.
The only intelligent entity on the island will be the spirit of a mad wizard who was the only person to predict that the island would be wiped out by a volcano.
He fused his essence into an eternal flame that he kept in his mansion outside the city. He can't leave a small radius around his eternal flame and has slowly been going crazy and losing his memory after the last 1000 years of isolation.
I'm planning for the PCs to meet the wizard, who will help them after much craziness. The wizard will explain that magical items can feed his eternal flame and they can find items in the city. They will explore the first couple levels of the city and find items and possibly some form of magical boat.
The magical items that the PCs gain from the city can be sacrificed to help the wizard gain some of his memory. The wizard will ask for help to find the elements of a super weapon called "The Tear of Sea" which this ancient sea empire was in the midst of constructing when they were destroyed. This super weapon had the power to control the sea after being soaked in sea water.
The longer the Tear was allowed to sit in the ocean the more power it absorb to the point where it could cause things like tsunamis.
Anyway it turns out the the first mate at the the very beginning, the one they have been chasing is after the same thing. The captain actually had royal blood from this ancient sea empire and he is the key to unlock some of the components of the sea weapon.
I'm planning for this island they are stranded on to become their home base. The capital city will have many levels so that it's impossible for low level characters to fully clear. I imagine the the PCs will go off on adventures, chasing after the back-stabbing first mate, getting clues towards the Tear of the Sea and getting stronger along the way.
Then they can return to their home base and clear out some more levels of the capital, gaining some more magical items from this ancient sea empire.