Check that the distance between waterline and water had not changed.
Seriously, how about no lines in the water or that may fall into the water. Dinghy line secure so it can't mess up a prop Oil level in engines Systems on such as navigation instruments, engines running and water discharging from exhaust, Weather forecast, consider windytv, swell forecast , consider windguru and windy tv Route planning Here's a start.
Warren S/V Scuba Doo Lagoon 50 (winner of best crewed yacht under 55 feet at the St. Thomas crewed yacht boat show).