Not being a lawyer I won't pretend to understand all the ramifications, but below is from their contract:

5.2 We also reserve the right to recall the yacht due to unexpected circumstances (e.g. severe weather conditions etc.) in which case we may give you a credit certificate for use on future charters, extend your charter, or cancel your charter. If we cancel your charter except for reasons beyond our control or as a result of your non-payment of any amounts due under the contract, you are entitled to receive a full refund of all monies paid. Notwithstanding the foregoing, no refund or compensation will be paid if your charter is cancelled due to unusual and unforeseeable circumstances beyond our control, the consequences of which could not be avoided even if all due carte had been exercised; such as (by way of example and not by way of limitation) war, riots, civil disturbances, industrial dispute, terrorist activity, natural or nuclear disaster, fire, adverse weather conditions, acts of God, unforeseeable technical problems with transport for reasons beyond our control or that of our suppliers, closed or congested ports, hurricanes and other actual or potential adverse weather conditions, flood, epidemics, health risks or pandemics or any other similar events or unforeseen circumstances that may amount to force majeure.