A few things
theThe spell is way too powerful,. aA 4th level spell that can fix a ship already exists,; it is called fabricate and it requires:
- Manymany castings
- the actual shipwreck
- lots of materials
- proficiency with shipwrights tools
- does NOT create a crew after it's finished
The simplest fix is to change the spell so it only floats a real shipwreck so itthat can then be towed to town for repairs. That would be OK for a level 4 spell. This will make a lost ship a big issue but not a complete loss. LoosingLosing a ship should be like loosinglosing a castle: it should require a lot of effort to fix. gettingGetting to the shipwreck will require an investment of time and spells, and theythe party will need to pay another ship to do the towing. Then they have to pay for actual repairs.
I have run saltmarshSaltmarsh and that would be the bare minimum if my playerplayers lost their ship, loosing. Losing a ship should be like loosinglosing a town you are defending, it--it should be a huge ordeal to recover IF it is even possible. I likely would make the cost of repairs at least half the cost of a new ship.