If you're not going to play water maps, be sure to at least know which maps are water maps so you can avoid them. Quite often half way through a water game, someone quits because they rush then discover it is a water map.

Know Where the Oil Spots Are
Make sure you either memorize each starting position and where the Oil spots are located for each spot, or print out all of the water maps so you will be able to find your Oil. If however you find yourself in a situation where you don't know where you are or where your Oil is, ask your teammates. If you have no teammates, send a Peasant around the island or edge of the water and attempt to build a Shipyard on the shore. If the Shipyard turns red, that means you are unable to build it because you're too close to Oil. That should let you find the Oil (on maps where the Oil is near to the shore).

Don't Lose Your Oil Rush to secure your Oil. Use Peasants to repair the Shipyard to complete it faster. Quickly Build an Oil Tanker and place it over your Oil Spot so the enemy will not be able to steal your Oil. The enemy may attempt to build an Oil Rig over your Oil Spot. Rather than attempting to destroy it, quickly build another Shipyard near your other Oil Spot and rush to grab the Oil there. If you're not successful at that either, attempt to use Submarines, Blizzard or Catapults to clear your Oil Spot. If you are not able to invade the enemy or get Oil you may never win the game. This is more of a concern on Low resource games but it can also happen on Medium and High resources as well.

Don't Build By the Sea (Including Your Town Hall)
Before building your Town hall on water maps, make sure you scout around and find a location that is well off the sea. Sometimes this isn't possible for a particular start location but at least place your Town Hall so only a few Ships can hit it at one time. If you build by the Sea, plan to control the sea to insure your Town Hall's survival.

[ Click to Enlarge - 57 KB ] Juggernaughts pound a Human Keep	[ Click to Enlarge - 51 KB ] Juggernaught attack some important enemy Orc buildings on the shore.

[ Click to Enlarge - 61 KB ] An experienced Water player finds the perfect spot to place the Juggernaught to hit the Temple of the Damned	[ Click to Enlarge - 62 KB ] A Juggernaught hits a Tower on the sea.

Try Not to Build Cannon or Guard Towers on the Sea
New players assume that Towers are the best defense against ships but, Guard Towers and Cannons Towers on the shore are only good against Destroyers, Submarines and Transports. Most players use Battleships to attack rather than Destroyers which can easily and quickly destroy Towers in a few shots. You can't rely on Peasants to repair the Towers. One Tower can be destroyed in 2 shots of a Battleship. Towers can only occasionally finish off a damaged Battleship.

If you *must* build a defense against a land invasion, put Flying Machines around the edges of the shore (or Peasants), then place some Mages a few paces back to Blizzard anything that lands. This is the most common and best defense you will see. If you are unable to do that, try to use Catapults and Towers.

If you have a small enough area to defend and enough resources, build a nice straight wall and put Towers and Mages/Death Knights behind it out of range of Battleships. Then when the enemy lands, Blizzard them, and the Towers will also fire on them. Keep in mind this should not be done when attempting to fight sea battles in most circumstances because the cost of building the Towers will mean less ships for offensive battles. Spend resources on offense first, defense second. This defense can destroy large numbers of attackers, even as many as 5 players at once on a map like High Seas Combat but the situation has to be perfect for it to work. Use Ogres to lay down Runes on the shore when the enemy may land. If you see a Human Transport landing start Blizzarding just in case an invisible Mage is unloading.

Don't Build Towers by the Sea When You Are Being Attacked By a Battleship
It is nearly impossible to build a Tower, complete it and upgrade it before the Battleship finishes it off. The Tower will be destroyed in one hit and you will have lost money and a Peasant. Instead build Catapults if you are being attacked by ships.

Don't Attack Battleships with Footman
The only things that can kill Battleships are ranged units such as Archers, Mages, and Catapults. Footman can only hit Transports that have landed on the shore.

Try Not to Attack Battleships with Archers
1 or 2 archers are not going to kill a Battleship unless the Battleship is severely damaged. There are just a few situations where you want to use Archers against Battleships such as a situation where you have lost control of the sea and you're down to your last units to defend. If you know the enemy has left a Battleship that has been severely damaged on the shore use hit and run hits against it with an Archer. Bloodlust Axe Throwers then send them in but make sure to spread them out. Cast Blizzards or Death and Decay to soften the ships up then send in an Axe Thrower to finish them off.

Don't Build a Destroyer as Your First Ship with Plans to Attack the Enemy
Do not send in a small number Destroyers to attack. Destroyers cannot easily destroy Battleships or ship buildings with their 2-35 damage attacks. Destroyers cannot easily kill an 1100 hit point Shipyard since they deal so little damage. By the time the Shipyard is close to being destroyed, the enemy may have a few Catapults to finish the Destroyers off. Destroyers just cannot deal enough damage in a short enough time to be worth using against buildings early in the game. Your first attack ships should be Battleships unless your plan is to use Destroyers to kill Transports. Use Destroyers for attacking Transports, Gryphons and Flying Machines.

Advanced players have developed a Destroyer rush where you depend on superior control against Battleships using hit and run tactics with Destroyers while the Battleships fire over it. This also requires a special building order to produce the optimal number (the most) of Destroyers in the shortest amount of time. It should not be attempted in real games unless the player knows what they are doing.

Don't Repair the Shipyards, Foundries, Oil Refineries While They are Being Attacked
Know when to quit. The only reason you should repair a Shipyard while it is being attacked is if a ship is about to pop out and it will only pop out if the Shipyard is repaired, or there are reinforcements on the way. It's bad to lose a Shipyard but large numbers of Peasants should not be sacrificed in attempts to keep it alive unless it's absolutely necessary.

Repair Buildings Being Hit By Battleship When There Is No Way You Can Stop Them As seen here, if you have only one Shipyard, without a Foundry, against 2 enemy Battleships and a Flying Machine, it's time to let the Shipyard be destroyed rather than sacrificing Peasants to keep the Shipyard alive let it be destroyed. By repairing the ill fated building you are just eating up valuable resources. Go build another Shipyard or building elsewhere. If your resources are limited you can't just keep repairing that building forever. If you continue to repair you're either going to lose more resources, or a lot of Peasants trying to repair it while it's under fire. This is also the case the Town Hall is being attacked. Build another Town Hall further away from the sea. The only reason to repair something is if a unit is about to pop out and you are reasonably sure you can kill the units attacking your Shipyard. After the units pop out, let the building be destroyed.

Don't Build Submarines as Your Main Attack Force Not Knowing How to Properly Use Them
Submarines can be very effective when properly controlled when the enemy enemy does not yet have Flying Machines. The Trick keeping Submarines alive is to move them after they fire. When moving, Submarines are less likely to be hit by Battleship's Attack Ground. If Submarines are left in the same spot, the enemy will be able to figure out where the Submarines are and can kill them using attack ground, even without a Flying Machine. Pick a random movements for the Submarines so the enemy will be less likely to figure out where you will go next.

Submarines have a greatly opportunity to catch the enemy at a disadvantage due to lacking of Submarine detection, Once the enemy has Flying Machines, Submarines can be used to pick off Battleships left around the map if the enemy does not have proper Flying Machine support. Use Submarines in hit and run operations. However, once the enemy is prepared to fight Submarines, quit using them. Don't continue to use Submarines throwing them uselessly against the enemy if they are not accomplishing anything.

Don't Build Oil Refineries without Plans to Build a Huge Navy
Oil Refineries are useful when six or more Oil Tankers just aren't bringing in enough Oil. At that point if you are building constantly from two Shipyards and still do not have enough Oil, it's time to consider using an Oil Refinery.

Quite often finding an Oil Refinery with only one Shipyard is a sign that the other player doesn't know what they are doing as building more Oil Tankers and another Shipyard is a better strategy.