Crystalis

I was stuck for weeks by the whirlpools years ago when I first played this, so I can definitely understand the confusion, and feeling like there is no where to go. There is a bit you need to do, and I am not sure where you are at in the game. So, I will give a quick list of places you need to go while assuming you got the Fog Lamp and have free roam of the ocean with the dolphin aside from whirlpools.

In order:
Joel Island - Talk to everyone, having not played in a few months I am not sure of specifics, but you';ll get info on a sacrifice being needed.
Evil Spirits Isle - Far to the west of Joel will be a cave, with a squid or octopus in front of it, kill it, then go in and navigate the cave until you come to a town of zombies. Explore the town until you find one person you can talk to, and talk to him. The entrance to Sabera's castle is at the end of the village.
Sabera's Castle - Solve the dungeon, and kill Sabera.
Back to zombie town - Find the guy you talked to previously to get Glasses.
Back to Joel - Find the guy who first told you of the sacrifices being needed. Use the glasses you got in the zombie village to show you a hidden door. Go through to find one of the main 4 dudes sleeping. Alarm Flute him awake, and he will leave behind a Statue.
Far far west of the map, search until you find a temple, shrine thing (another squid or octopus guarding it) and use the statue you just got.

The whirlpool blocking the way is now gone.