What is the single most useful habit this whole incident teaches about leaving a dinghy unattended ashore?

A. Always think about how the tide will change before leaving any small boat on a beach, and tie it to something secure rather than relying on it simply staying in place — a few extra seconds of care prevents this entire chain of events

B. Only the dinghy's owner needs to think about where it is left, not the rest of the crew

C. Dinghies should never be taken ashore under any circumstances

D. There is no reliable way to prevent a dinghy drifting away once left on a beach

A. Assume it has sunk and stop worrying about it immediately

B. Wait several hours before checking on it again, since it is "just" a dinghy

C. Check that no one is in or near the dinghy and that it is genuinely empty and adrift, not just out of sight behind something — then keep watching its position closely so it is not lost track of completely

D. Swim out after it immediately without telling anyone else what you are doing

A. Only large boats need to think about tide when leaving them unattended

B. Tides never affect a dinghy that has been pulled up onto a beach

C. This kind of thing cannot be prevented and is simply bad luck every time

D. A rising tide can lift and float away a dinghy that seemed safely beached only a short time before — dinghies should always be tied to something secure on shore, or pulled up well above the expected high water line, not just left resting on the sand