Battlefleet Gothic was themed on battles incorporating space-faring fleets of the different races highlighted by the Warhammer 40,000 universe canon. (wikipedia)
Wikipedia: Battlefleet Gothic is a tabletop miniatures game based in Games Workshop's fictional Warhammer 40,000 universe, and is sold by Games Workshop.
All at Sea (ruleset) - All at Sea is a naval ruleset for Games Workshop's miniature wargame The Lord of the Rings Strategy Battle Game. The official rules were a modified version of the Warhammer Boat rules, adapted by Nick Davis and first presented in Games Workshop's White Dwarf magazine.
Man O' War (game) - Man O' War is a now out-of-print table top war game by Games Workshop. The game was set in the same realm of Warhammer Fantasy as used for the Warhammer Fantasy Battle and included most of the factions from that setting.
Space Fleet - Space Fleet is a board game for 2-4 players, published in 1991 by Games Workshop and designed by Jervis Johnson and Andy Jones.
Full Thrust - Full Thrust is a science fiction strategy wargame written by Jon Tuffley and published by Ground Zero Games of England. It is usually played with miniature figurines representing imaginary starships, although cardboard chits representing the vessels can also be used.