How do i get to Boreas Seabed?

I have been trying to get to cavalon, for the faction transfer. But i cannot get into Boreas Seabed(theres a gate). Is there a quest that i need to do that lets me into Boreas Seabed? Or do i need to complete the kurzick missions first, i'm at Arborstone. If anyone knows where to find the quest please tell me.

Yep you need to complete missions to access boreas. What's more is that after you do boreas; you need to complete another string of quests AND another mission to access cavalon.