Sea Units
Oil Tankers
These units are for building oil platforms and transporting oil. The are almost like peasents and peons.
Elven Destroyer and Troll Destroyer
Elven Destroyers and Troll Destroyers are the first main line of defense on sea. The (just like all destroying ships)can be upgraded to be very strong.
Battleships and Juggernaughts
These are the buffest ships. They are awsome if you have them totally upgraded and have a lot of them. The cost lots but take an average amount of time to build. They kill!
Gnomish Submarines and Giant Turtles
These are under water and can not be seen by anything but towers and flying units. The attack is ok and they have no armor, but they are good spies.
Transports
These boats are to allow you to take infantry and catapults(ballitsas too)to other lands. You can fit only six units in one transport
.
Air Units
Gnomish Flying Machine and Goblin Zepplin
These units are for scouting only. They scout an enormous amount of space and fly very quickly. They can also be used to spot underwater objects. The only thing else that can see the underwater objects is towers.

Griffins and Dragons
These units are perfect if there is nothing
that the enemy has to damage flying units. They fly very fast. Their hit
is a little wimpy and they take a long time and lots of gold to create
but they are worth it
Sea Buildings
Shipyards
These buildings are like a barracks on sea. They create all ships you will ever need!
Foundry
These are for upgrading you boats to make them more durable and stronger. They also allow you to build transports and battleships.
Oil Refineries
These buildings increase your oil production and you can return oil here.
Oil Platforms
These you have to put up to get oil from the oil patches in the sea.