you can pay for and buy a house or land,but you cannot "own" a house or land.
If you think you own your house or land. Try not paying your taxes and you'll soon find out you have been renting.
The same is not true for a sailing vessel. which ,of course , can become mobile quite faster than a house. If the neighborhood goes downhill, cast off.
If the political regime gets ugly,cast off. if your tired of the scenery, well... you get the picture.
As far as the investment argument. I purchased the boat for me, not the next guy.
boats do in fact sink (unfortunately). Ever witness a house fire ? earthquake,tornado,sunami. how about a major miltary conflict ? try to insure against that one !
Life can get pretty ugly for the relatively short time we each get to spend at it.
My only major current regret is that I' wasted so much of it listening to other's ,wasting their lives, telling me I was nuts for wanting to live mine.
Live the Dash, in the end it's all you'll end up with.