But now I'm stuck solid!

How the hell do you get the sail?

Here's how to get it:
"Follow the Sail Map to (204, 3) until it points directly downward. Press Up to reveal a cave entrance. Climb the cave, and talk to Mother-Father towards the right end. Travel left, use a rock to activate the elevator, climb up further until you reach a waterfall. Sail across, use the wind in the next room to ascend, hit the green switch, travel up further, push the blocks onto the red button (don't push the lower block all the against the wall). Exit the room, climb up further, jump across the gap with the wind, head upwards, use the parrot to drop a rock onto the yellow button, and exit. Climb across the top of the waterfall, and enter the general store. Push the blocks onto the three green switches (middle to left hole, left to middle hole, right to right hole), and open the chest."
From this website:
https://jayisgames.com/review/treasure-adventure-game.php

Nope, no dice there. There's no cave entrance at all - and it's (-204 , 3) not (204 , 3)! I haven't got the "sail map" yet though, NVM the sail! Still stuck!

I see! Thanks SCPM. I'd have not likely ever noticed that hidden entrance at all! Hope there's not more like this in the game!

No problem!