Colin has recently invested in a pile of Topside Minis WWII ships, and they come with a brutally simple set of rules. We gave them a try last night in a very small, relatively quick, game. These are the rules. They're about four or five pages long, and cover everything from gunnery to aircraft and submarines.
The ships are gorgeous 1/2400 colour top-down images on chunky MDF bases.
We played a small game - Japanese vs Australian/US, with a cruiser and two destroyers on each side. The game uses D12 to determine hits and fixed damage. There's very little granularity in how ships are classified; it's not a game for rivet-counters.
Anyway, the Japanese won it - they lost a destroyer, but sank the Australian cruiser and a destroyer, leaving the surviving destroyer to flee.
I suspect the rules aren't designed for the small game we played (albeit it that it was fun), but are designed for fighting huge battles where fiddly detail about the differences between vessels bogs the game down. It would certainly be interesting to fight a larger action, with aircraft and a wider range of vessels.