entance to devils isle

I went to go down there and ended up on a pier that was a dead end. I see a tunnel on the map. Where would I find it?

Thanks in advance ^^

you have to swim the line is just that a line on the map there is a under watter tunnel that leads inside be sure to get kiss of eva first tho you will prob need it. hine sells kiss of eva pots also drink it before you get in the watter or it wont take effect

Hope you brought your swimsuit.

And your shark repellant.