I played the heck out of the Mac version in the 1980s. I was only able to max out the score once, on a perfect run with the stars aligned. The key tactic was to delay the relative rescues until very late in the game, and to find one treasure per relative - that is with just 1/4 of the map. I had basically memorized the game's bitmap of the Caribbean. I suppose if you tried it today, you'd probably look for a data-mined version online.