A fire like this would consume all the oxygen in the boat atmosphere and hypoxia would set in on the crew pretty quickly. Any firefighting they could do would be impaired by diminished capacity. And the end would be pretty quick.

https://www.cnbc.com/2022/01/29/electric-vehicle-fires-are-rare-but-hard-to-fight-heres-why.html

A fire like this would consume all the oxygen in the boat atmosphere and hypoxia would set in on the crew pretty quickly. Any firefighting they could do would be impaired by diminished capacity. And the end would be pretty quick.