There is a large blue cooler by the stairs in the boat, under two postcards. But in the shot where Jason clips the harpoon, before shooting it, we can see the cooler has vanished.
Jensen Daggett was genuinely terrified when actor Kane Hodder pulled her towards him, through the porthole. This is because a huge shard of glass was right by her throat and Kane was unknowingly pulling her toward it. You can see the frightened look on her face.