Has anyone beaten the mission called the Ship? I've tried it a number of times and I can't quite get around the huge unit advantage the AI has. If anyone has any tactics they used for this map that worked, I'd love to hear them.

The main thing to try to do in this mission is to get a quick start to balance out the initial town advantage the enemy has. Your initial army of elves will slowly desert you, so you'll need to move fast. Start by heading east and capture the enemy sylvan town, then focus on building up its gold producing capability (since any sylvan creatures you hire will just slowly abandon you there's no point in trying to quickly build up it's production capabilities at the expense of building up its gold producing capability). After taking this town immediately have Agrael head north and east to a stairway to the underground. Your target is the demon town that lies in the south center portion of the underground- this town will be your primary source of troops, so once you take it build up it's army-production facilities as quickly as you can. The enemy mostly just has low-level heroes and they don't start with particularly powerful armies, so the initial army you start with should be able to get you this far without much trouble.

From here there are two more enemy towns that will send troops at you, to the northeast and northwest of the first sylvan town you captured, so once you build up a bit of an army capture them at your leisure. Once you've done this you don't have to worry about the enemy sending anything at you, and just need to build up enough of an army to take the town to the very north of the map (which has a pretty strong garrison). If you're finding the garrison of this town too tough for just the demon forces you can produce (since you only have a single demon town), one trick is to let creatures accumulate in the captured sylvan towns (but don't buy them), then when you're ready to take the town to the north buy the stronger creatures that have accumulated (Emerald Dragons, Master Hunters, etc)- they'll still slowly desert you, but if you just make a beeline for the northern town once you hire them you'll still have the bulk of them when you assault the town (and your three sylvan towns all producing Emerald Dragons can build up quite a force pretty quickly).

Another thing to make sure you do at the beginning of the map (once you capture the first sylvan town) is to hire a throwaway hero or two to scout around and pick up any free resources. This ensures that Agrael is spending his movement on critical objectives (capturing the demon town, then the two other sylvan towns), rather than wasting his movement scouting around or collecting resources (one of the common mistakes people make in Heroes games is wasting the movement of their stronger heroes on tasks that throwaway heroes are better suited for- you can have your stronger heroes run around exploring the map once you have the upper hand, but until then their sole mission should be taking the fight to the enemy to ensure that you get the upper hand as quickly as possible).

Thanks, that helped alot. The mission following it is a breeze by comparison.