I have a similar interest in sailing the ocean and have a similar tendency to hold on to sentimental stuff. Then a couple years ago I found a simple solution. Driving along the coast, way out in the boonies, I found a couple acres of land on a bay of water. Over an hour from the nearest town about 1000 people, so consequently relatively cheap at less than $20k. So now the plan includes a sailboat and a cheap piece of land where I can build a small coastal shack and concrete bunker. Hehehe.
Although I suspect that once I get close to actually purchasing that boat, then suddenly all that stuff will be just fine in memory and less important to physically keep. On the other hand, a concrete bunker might still be nice for the next zombie apocalypse....
