Boom Canon – This is the most effective tower defense against tank or any armored unit but its slow loading time is the downside for this defensive unit. It has a double damage bonus against tank. This unit will take 3×3 space from your area.
Canon – This is your primary form of defense that can support between the lines. Just like the Boom Canon it can also do double damage against tank so if you are in opposing force and you see canon you better take down these defensive unit using gunboat artillery and barage. This unit will take 3×3 space from your area. Canon is perfect not only for tank but also any units that having massive amount of HP.
Machine Gun – If you have canon for heavier unit, you can also use machine perfectly for low-HP unit that usually come in number such rifleman. The total advantage of Machine Gun in game is at close quarter combat. Since the effectiveness of machine gun is based on close fight, you should put it as frontliner defense. While in dealing with machine gun as opposing force, you should let your tank do the job in eliminating machine.
Flamethrower – Just like machine gun you will use flamethrower as your primary defense against massive numbers of units. This is for close quarter combat that can instantly set all footman to burn for a matter of seconds. The same as for machine gun, flamethrower is helpless against tank so if you are in opposing force and in dealing with flamethrower, you should place your tank to take down them all before your infantry. You can consider placing flamethrower in front of sniper to cover up short range issue.
Mines – Instantly explode when opposing enemy comes nearer. Since players can’t control their unit as they deploy in the battlefield it is very prone on taking damage from Mines. Effective placement of mines can give you enough advantage to win the game. Your guide in playing is anticipating the movement of your opponent based on how you perceive the situation. Of course like them, you can also attack other base and from here you can anticipate their action. You can also based your placement from other players’ strategy if you think that this is effective and got work with you.
Mortar – This work as splash damage dealer from your defensive unit. Unlike with flamethrower, Mortar can handle medium to long range and the best position for this unit is in the center of your base as it can handle attacking unit from all direction but still helpless in short distance. If you are in opposing force, you can eliminate mortar using gunboat artillery or any other unit that can attack it in short distance. Though with high damage it can inflict, Mortar has a poor reload time that make this unit vulnerable against fast opposing unit.
Rocket Launcher – Overall this is the most powerful defensive piece you can use in game but also vulnerable in short distance attack. Compare to Mortar, it has a reliable reloading time that can make them almost invincible for most opposing units. This unit doesn’t have preferred target as it can do massive damage against everything in long range. Being helpless in short quarter combat, it is perfect to build with defensive unit specialized in short distance such as flamethrower and machine gun.
Sniper Tower – Compare to other defensive unit, sniper tower can inflict damage against individual. Though it has poor rate of eliminating hordes of attacking theme, still the reliable range made this tower so useful. If you are kind of players who know how to use range as part of their best strategy in Boom Beach, you might consider empowering your entire defense system with Sniper Tower.