Your contract will have a damages clause, I'm sure. They may limit responsibility for certain elements of damage. There certainly is no obligation to give you a "loaner."
You are likely looking at a claim for diminished value, after repairs. What type of boat? Age? Value?
Are you making claim on their insurance? Yours?
With nothing in your marina contract then they would be responsible for repair cost, even if you get someone else to do the repairs and all the incidental and consequential damage, such as loss of use or renting another boat. But ... there most likely is something in the contract that limits damages. OTOH there may be something in the MD Code that limits such limitations, pun intended. (There is, for example, in the part that deals with sale of consumer goods.) Not being your lawyer, I am not going to research whether there is such law, and it would depend whether you use the boat for recreation or making your living.
But the starting point is to read your contract, the fine print.
If the boat is worth hundreds, or was just before the incident, make the best deal you can with them. If thousands, or your tool for making a living, consult a lawyer who does marina law.
BTW, why are you letting them repair a boat that is beyond repair, and that their people broke by being so incompetent as to try to use the wrong slip?
Licensed in Maryland with offices in Maryland and Oregon. Information here is general, does not create a lawyer-client relationship, and is not a substitute for consulting with an experienced attorney on the specifics of your situation.
As the other lawyers have indicated, the answer depends on the terms of your contract. Any or all of your options sound like a reasonable accommodation. On the plus side, it sounds like they have accepted responsibility and are trying to make good. That is more than half the battle.
*** LEGAL DISCLAIMER I am licensed to practice law in the State of Michigan and have offices in Wayne and Ingham Counties. My practice is focused in the areas of estate planning and probate administration. I am ethically required to state that the above answer does not create an attorney/client relationship. These responses should be considered general legal education and are intended to provide general information about the question asked. Frequently, the question does not include important facts that, if known, could significantly change the answer. Information provided on this site should not be used as a substitute for competent legal advice from a licensed attorney that practices in your state. The law changes frequently and varies from state to state. If I refer to your state's laws, you should not rely on what I say; I just did a quick Internet search and found something that looked relevant that I hoped you would find helpful. You should verify and confirm any information provided with an attorney licensed in your state.
Generally speaking, contract damages are: cost of repairs + reasonable cost of renting an equivalent boat (actually incurred), or if you do not rent another boat, then the pro rata share of the marina fees you incur during the time your boat is not usable. If the boat, as repaired, is worth less than it would have been had there been no damage, then you may have a claim for diminished FMV. Your marina contract, as mentioned by others, may have limitations on liability, and may (typically does) have a provision requiring you to maintain your own insurance to cover the risk of accidental damage to the boat, although sometimes the negligence of the marina is excepted from this requirement. You are not entitled to your boat payment (toward purchase price) or insurance payments during the time of repair, under any theory of damage law.