It wasn't actually one-man boarding action. Prat and two others attempted to board (his order to go wasn't heard over the noise of the battle) and he was killed on the deck of the Peruvean ship.
http://en.wikipedia.org/wiki/Arturo_Prat
The ship, the Huascar, was later casptured and brought into the Chilean Navy. She is still afloat and preserved as a memorial in Tulcahuano (I've been lucky enough to visit her)
Also, as a friend of mine discovered when we were in Chile, dissing Arturo Prat (especially in a Chilean Navy town) is NOT recommended in front of the locals!