Several acid flasks? The break spell twice (or once and then use tools)? As far as a low level sorcerer your spell options aren't very good, you could try burning hands or corrosive touch they would probably get the job done. You are the GM so you have some wiggle room as to how spells can be used.
Well since it is a ship, I figure break would not affect it (as a ship is too large). However, if you have the minions hack at the hull for a round to break a portion, then cast break on that portion it should work. 6-12 seconds to break into a ship is not bad. Also, if any of the minions are strong enough, have them attempt to break it (rather than beat at it's hitpoints), with a STR check, DC 18. Then cast break.
Alternatively, if you go with the wizard he can cast 2nd level spells at 3rd level, and there are a good deal of fire spells at 2nd level that deal a good amount of damage and could probably burn open a section of the hull. Fire breath seems the best for that option, or flaming sphere.
a portable hole might work. They put the hole on the ship hull just above the water line, the ship begins to take on water, they steal loot and leave the ship slowly flooding with water.
Gauntlets of rust could do something similar if it were a metal boat.
|
Staff of Passage on it's last charge, perhaps? Stolen, of course, with an angry wizard who'll find it, expended, in the PC's possession...
Wood Shape is plausible.