Any reputable Yacht Charter Company makes it clear what is covered by the Boat Insurance, the Yacht Charter Insurance and the Yacht Charter Conditions
A Yacht Charter Company normally asks for a security deposit to cover smaller losses and the insurance excess in the event of an accident or loss.If their excess is very high it could be worth taking out an additional insurance to cover the excess.
The Insurance does not normally cover personal accidents or illness and it is therefore sensible to take out personal accident insurance for the period of the charter and also to cover the possibilty of forced cancellation due to illness or other causes.
The Conditions of Charter should be fair to both sides including the arrangements made if the charter yacht becomes unavailable.
Typical Booking Form and Conditions of Charter