The most you are liable for is $5000. (Normal insurance conditions apply)
Please note that the security bond is a condition of your charter and is not a type of travel insurance.
If you are covered with the recommended travel insurance, you would be able to make a claim on the travel insurance policy for the majority of the security bond should you damage the boat.
This could also cover you if there is a problem with transport ie. airplane flights etc, if you are coming from overseas or interstate.