In the random free time I've had, I've been playing a lot of Warcraft 3 Custom Maps. Big one I've been playing?
Battleships Ghostbay
AoS kind of map, except it's all water. Players control a ship (starting with the basic Sailor, all the way up to the mighty Ghost Ship) and work to destroy the opponent's harbour. There are a bunch of maps in this series (Pro, Crossfire...), though Ghost Bay is probably the most-played one. It's much more forgiving, and levels/money come a lot slower. Interesting map. I also feel like ranting, so...ship rankings!
Sailor
Everyone starts with this thing. If for some reason you want to purchase one later? 200 gold. Really, really bad. Slow, frail (second frailest, after the Trader), skills aren't anything special. Although, of note, it does have Captain's Cannon, which is a decent nuke against other Sailors, due to frailty. As for skills, you have the Cannon, Hull Boost (HP boost, present on most ships), Sail Boost (speed boost, present on most ships), Repair Crew (Regeneration boost, present on most ships). My usual build is Hull Boost and Repair Crew, to last a bit longer and to go with the close-range cannon barrage early. Other viable options are mass rockets with Sail and Cannon/Repair, or a combination thereof. It's hard to go wrong, since the ship is so weak overall - it's just specialization.
Trader
REALLY. REALLY. FRAIL. Seriously, 75 HP. You CANNOT use this ship for serious combat. And it's only available in certain modes. So what does it do? It trades. This is only kind of useful to start, but once a trader gets going and starts surviving, they can finance the entire team in seconds, do some crazy damage to the enemy, or, alternatively, finance themselves into a monstrosity in the course of a few minutes. Unfortunately, you need to be competent - a dumb trader is not helpful, and only serves to feed money to the other team (every ship is worth a different bounty when killed - Traders are worth as much as the mid-tier ships), and if one team has one and the other doesn't, that team without one needs to make sure they kill it and keep them from building up. As noted, the early trading is weak, but it gets exponentially better. Thankfully, playing the Trader is made a bit easier - skills are designed entirely for survival. Divine Shiled (invinicibility), Decoy (...uh...makes a decoy), Fog (invisibility), Sail boost (as above) and Teleport (...dur...). Still, the Trader needs levels to get those, and ideally, needs to save up for a sail to start with to make things go faster. I am not great with Trader, although I enjoy hunting them. I...have played it once, and really...did ok, not outstanding. Can't comment on it too much otherwise. Worth noting that you need a little money to start (costs 400, you start with 200) using the Trader.
Crusader
The early-game ship everyone likes to use. 750 HP, decent speed, some armour, and a shitload of skills. Sail boost, Hull repair, Net (disables a target, preventing them from moving for a short period of time), Fog, and Capsize (suicidal explosion that does a bunch of damage). The Crusader is also cheap (1000), and also fun to annoy people with. It almost necessitates getting something to sight invisible targets with, as Capsize is very powerful - at max level, it deals 1500 damage, with 300 damage to all surrounding targets. Ships below Dominator will be killed unless they have boosted HP a bit. The Crusader is a hero-ship killer, no doubt about it. Invis with some good guns, net, blow the hell out of a ship, cap if you're going to die (taking someone with you and denying them money/experience for the kill). A lot of people jump to this as the next tier after Sailor, as it's cheap and effective. It's even useful late-game as a raider, and played well, can do some major damage. Also great for Rage-Quits. Biggest issues are that it is frail later (750 HP is not much), and you can counter it with a Goblin Scouter (although this is an advantage too - it takes up an inventory slot that could be used on something better for combat, and has a slight cost to the opponent).
Interceptor
One of the three second tier ships. This one is all about speed, the fastest ship in the game. Decent enough HP and armour make it a huge step up over the Sailor. Skills are really more helpful than they look - Hull Repair, Sail boost, Hull boost, Intercept (large speed boost for a time), Disrupt Beacon (prevents other ships from using special skills - including things like Capsize). One of these on the team is really helpful, and this is another ship that works great late-game if played right. Cost isn't even bad (1200). These things are good raiders, and Disrupt Beacon is a great Crusader counter. No real weaknesses that stand out - it is a bit weak in terms of ship strength (hull, regen, armour, etc.) end-game, but the skills are very powerful, and it can hold its own.
Sea Punisher
This is the last of the second tier ships, and the most team-oriented. Skills are...unique. Healing Wave (group healing), Hull Reconstruction (heals a ship over a few seconds for a decent amount of HP), Hull boost, Hull repair, Big Bad Voodoo (invincibility for allies). Good armour and HP. Really slow, though. This thing needs a sail to be useful late-game, and even mid-game. Very powerful in a team's hands when used correctly. Of course, getting that in public games isn't always easy! But yeah, this ship is the most advanced of the three second tiers (Crusader is the easiest, Interceptor is in the middle), but can do a lot in the right hands. Used properly, I've had Bib Bad Voodoo be exceptionally useful in slaughtering an opponent team (ideally, the ship needs some items to make this last longer, particularly a hull), and the heals can save people from Capsizing Crusaders, and a mix of other attacks. Always like having one of these, and if no one else takes one, I usually do. Cost is barely more than an Interceptor (1300).
Dominator
Third-tier ship. Costs 2200. Is probably my favourite ship, and a great one to even end the game with. Skills are Hull Repair, Hull boost, Sail boost, Electromagnetic Pulse (large area damage that slows ships hit), Teleport (...uh...). Good HP, enough armour, skills are great, though do require some experience. EMP in particular has a charge-up time that people don't realize - if you see a Dominator stop, even for a second, RUN. It's 500 damage, which is a lot to handle for smaller ships, and even damaged ones. The ship isn't even slow - tied for 4th with the other ship in its class. Overall great ship, that can benefit from any number of approaches to its use.
Destroyer
The other third-tier ship, costs a bit more (2500). Same speed, skills are Hull Repair, Hull boost, Sail boost, Board Ship (stops a ship in place and deals damage to it), Slow Aura (slows down opponent ships). This and the Dominator are very close for effectiveness - Slow Aura is a different take on Teleport, with less initial jump, but helps the team out and doesn't require active use. Board Ship is...better than EMP for getting more hits in, but doesn't have the raw, immediate damage. Destroyer is a bit more durable than Dominator, but overall, the ships play very similarly. Tactics that work for one work for the other. The third-tier is generally the tier I will stay in the longest, as the upgrades you buy for them work well enough in the next tier anyway.
Overlord
Tier four. Overlord is big - more HP without Hull boost than a maxed Destroyer with a high level hull. Skills are Hull boost, Hull Repair, Sail boost, Send Spy (gives sight of everything an opponent ship sees), Freeze Water (advanced EMP - stops target for a while and deals more damage when leveled). A bit expensive (5000), but also is surprisingly faster than it seems. Plays a lot like the Dominator, although the Freeze Water range is a bit shorter (but more powerful, so it balances). Probably the biggest ship that sees use in casual play, though a great ship nonetheless - these things can tank for a while, and do some massive damage if used right.
Admiral Ship
The other Tier four. 8000 gold, which is a good chunk, but also has loads of HP, and is pretty fast despite its size (3rd fastest). Skills that stand out (the normal 3 the others ships had still count) are Sail Ripper Cannon (300 damage and slows ship for a bit) and Overrun (large AoE random hitting attack that deals good damage to anything it hits). Overrun is good for clearing the base, and taking out ships at a distance (it has a very large AoE). It is a bit expensive, but feasible to access. Great ship, and I consider it the practical ultimate of the game. It can hero and base kill well, and is durable.
Ghost Ship
Tier five, the ultimate ship. 15000 gold. 2nd fastest, highest armour, highest HP, etc. Skills are Hull boost, Hull repair, Sail boost, Ghost Raiders (ultimate skills that drains HP from opponents). Way too expensive unless there's a good trader, or the other team is retarded. Granted, really tough to kill, especially with the right set-up. One can take out an entire team if used correctly (and the other team has no teamwork). But...too costly to really be useful, for me. Otherwise is the ultimate ship, though!
So...generally, I will jump either straight to Dominator, or go for a Tier two if needed. I prefer the Interceptor, but will use the Punisher if we don't have one. Of course, I'll have to talk about weapons next! Maybe in a later post >_>