Bolwag was a male sea lion who helped Vurg and Beau build a seaworthy raft to reach Wood Isle in one piece. Bolwag used bladderwrack, a floating sea plant. He pulled the raft until Kweekum and a group of bottle-nosed dolphins showed up. They were friends with Bolwag and allowed him to rest.
The raft was mostly constructed out of the debris of Sayna, the ship Luke the Warrior had sailed on until the Goreleech rammed it.