The water tank access door falls down while wrestling hoses and other gear in and out of the compartment. There’s a brilliant little device that will solve this problem. They are called baggage clips or latches. They are available here on amazon for about $6 a pair. JR products makes higher quality plastic items for the RV industry than the cheaper ones, it’s worth the extra couple of dollars.
To install one, hold the door open and see where the latch needs to mount on the Casita. Mark a hole and drill a 3/16″ hole into the fiberglass. You want to stop as soon as the bit goes through the fiberglass and avoid drilling through the foam and carpet on the inside of the Casita. I used a dab of white silicone in the hole before installing a 3/16″ pop rivet. Once that rivet is in, make sure the clip is straight and drill the other 2 holes and rivet them as well.
Now I can access the hatch and even watch the water level while filling the tank, hands free!