Roundabout way to cavalon

Exit Zos Shivros and run to the portal to Mount Qinkai. Travel through Mount Qinkai and run to the outpost Breaker Hollow. Then go through the east exit into Archipelagos and make your way to Cavalon.

The only requirement for this way is that you have Boreas Seabed finished. The way Azazel pointed out isnt entirely correct - your whole party needs to have completed the Befriending quest in order to get through. First, let me say that I did not know of the way you mentioned. Second, your party only needs to have compelted Befriending the Luxons when going to Gyala Hatchery the correct way (i.e., heading south, not north - heading north, you just need to do the Kurzick Side). Unless, of course, they changed it since the last... 6 months? idk, been a while since I went through that way (and although people say you need to have done Befriend the Luxons (or was it Journy to the Whirlpool) to get to Unwaking Waters (Luxon) from the other side, I didn't (do either quest) and I got through, several times).