Weather can be fickle. If you're in a tropical climate there can be rain and then sunshine on and off throughout a single day.
Cancelations due to weather happen. It's part of the industry and the risk in booking an experience that involves the outdoors.
As with other cancellations, weather cancellations are subject to the owner's cancelation policy. Most owners will offer a full refund or a rescheduled date. However, owners are entitled to request payment if it's determined that the conditions are still safe to go out on the water.
GetMyBoat understands some trips are booked with the expectation of sunshine. But if the sea conditions are safe where a charter or rental can still occur, canceling due to unsatisfactory weather does not necessarily mean a refund is warranted.
Most owners will be flexible or understanding regarding weather cancellations. However, unless the Coast Guard issues an advisory or prohibits watercraft from going out on the water, any refund request for a weather cancellation will still need to be approved or authorized by the owner before GetMyBoat will issue a refund.