Ok pirate island has just come under attack I have been giving orders to talk to my dad in the underground base i'm having trouble trying to find the entrance!

I can get underground via a stone door inside is a young boy and woman who tell me to speak to the captain further on is a chest containing a moonberry although I can see other villagers on the lower level I can't get down to them ( no ladder )

I can't leave the island as I have to speak with the captain

Any ideas?

First of all if you are on about the part of the game in which you return to shrine island then Vyse's dad is not down the underground as he is caught in Valua, but you do have to go down there to meet Vyse's mother.

The problem is the stone wall you went through is it's meant to be a secret bit with a moonberry in the chest...

You should go out the way you came in, that is another stone wall but it is near the edge of the island unlike the one which you tried to go through which is in the center...