Not about Costa Rica, (it's Belize); and not specifically about live-aboard; but you might be interested in seeing how this type of issue is handled elsewhere in the region.
Also, by looking at these sites it might make your google search for similar information about Costa Rica a little more fruitful.
Retire in BELIZE - Belize Retirement Incentives Program - Terms and Conditions
Website of the Belize Tourism Board
I got an Old Fat Boat
She's Slow But Handsome
Hard In The Chine, but Soft In The Transom
I Love Her Well, And She Must Love Me
But I think It's Only For My Money
. ..... Gordon Bok