I was playing this just last year.

The game is called 'Robinson' (Robinson Crusoe) and is now a cell phone game.

http://games.mob.org/game/robinson_crusoe_shipwrecked.html

Old-games.com. They're literally stealing content from Underdogs for years.
Old-games.ru is OK, however.
But not oldgames.ru - that's pure shit.

I wonder if anyone was correct so far or should we keep guessing?

I think this was it, for the 64, but I played a special Dos version that according to another forum was specific to my school board.

"It's the one where you press numbers 1-9 to either collect planks, fish, message in a bottle, or try to swim but you have to be careful of the sharks!! "

took that from another forum, and it describes it perfectly

Dear baby Jesus,

When you come to earth to drop the big one, and smote the sinners for what they have done, bring Ghorpm back to heaven with you.

I'm glad I could help ;) I had this game on C64 but my English was very bad at this time and I didn't really understand what I'm supposed to do and therefore it took me some time to recall it now... but I think I will perhaps give it a try now...