I know there was a book in 3.5 that centered on naval campaigns, with classes for ship captains and rules for Narrative naval combat. Has that book been updated for 4e, or are there any other books in 4e with similar rulesets, or has someone got some homebrew rules that cover the same ground?
The core of the naval combat is from his basic combat rules (reproduced here in case the site goes down again):
This may be related to the question: Fantasy adventure modules with naval adventuring
Besides extending the standard classes with seafaring skills and spells and such, it adds several prestige classes: Knight of the Pearl, Legendary Captain, Leviathan Hunter, Scarlet Corsair, Sea Witch, Stormcaster, and Waveskeeper.
The narrative naval combat method is detailed in chapter 1. The first included encounter The Sable Drake is very verbosely described and seems to illustrate this method.
Sadly, I'm unable to find any mention of a 4th edition release date. :-(