Tug, this won’t fix your immediate problem, but may help in the future. Hidden in each of my boats, I have a flat heavy duty pouch, with a Velcro closure, made to hold keys. I purchased the pouch from a locksmith store, but they are available online as well. The back of the pouch is covered in Velcro, and the mating piece of Velcro is glued in a hidden area in my boat, that is not behind a locked door, or locked compartment. In the pouch is a key for the engine and a key for the door. Both keys are flat and fit the pouch easily.
After traveling in my first C-Dory, my wife and I were always concerned about loosing keys, so initially, we would both carry a set of keys, just in case. The pouch back up plan took care of the concern, so now we don’t worry about loosing keys