The colonial service Defender-class torpedo boats were designed by Thornycroft & Company for the defence of New Zealand, built at Chiswick in 1883 and shipped to New Zealand. They were quickly obsolete and were left to deteriorate in situ. The remains of Defender are preserved at the Lyttelton Torpedo Boat Museum.
As built the class was armed with a single McEvoy spar torpedo, which was designed to be rammed into a vessel and explode beneath the waterline. A single 2-barrelled Nordenfelt gun comprised the total gun armament. The last pair had 18-inch Whitehead torpedoes fitted at build, and these were later retrofitted to Defender and Taiaroa.