Indeed. The heroes must either successfully drop anchor (a surge, so 1/3) or suffer the red dice, which has 1/3 chance of killing them no matter where they are and 2/3 if they didn't use the wheel successfully to move one space.
Basically that is a guaranteed 2/9 chance of sinking the Revenge no matter what the situation is and what the heroes do, and if they survive that first turn they still aren't out of the woods. Unless they have a very fast ship (maximum sails and Elvish sails) they have to repeat next turn. So it is 32/81 chances of the Revenge sinking no matter what they do really.
Note that if they do drop anchor the only way they can get out of the encounter without raising the anchor and going through the same risk is to kill the encounter Leader - who can sit back and accumulate infinite threat while waiting for them to raise anchor and come forward (unless the heroes all leave the ship behind and swim out to attack the monsters - and trust me, this is not going to work without some very specific skills/feats/abilities and/or a stupid OL!)
Therefore I would argue that dropping anchor is not effectively a viable solution so it is really 1/3 chance of a TPK regardless of what the heroes do,
5/9 chance of a TPK in truth, over the first two turns.
If they do manage to survive the first round of current for two turns and get past the first rock, there are more rocks a couple of extra spaces west further along! So they can still be shipwrecked unless they continue to spin the wheel east and roll low range on the red dice.
It's just a botch job by FFG...
It would be fairly simply cured by changing the current direction to N/S so not into the rocks!