In order to get the "The Back Door" trophy in Burly Men at Sea, you need to lose the race after getting in the barrels and then take a right when given a choice in the tunnel.
(Remember to make cross saves before trophy related decisions to drastically speed up your play throughs).
Here's the steps from when you enter the Whale, which is an unavoidable incident at the very beginning of the game:
-- Talk to the girls by the fire
-- Go all the way left until you see three barrels, interact with them
-- Interact with them again after the dialogue
-- Head right and go through the door behind your ship
-- Scroll right, get through the dialogue
-- Interact with the uvula, get through the dialogue
At this point you'll get:
-- Swim right, dialogue
-- Scroll right, dialogue
-- Move the cursor to the blonde Burly (Hasty Beard) and hold X until he falls back to last place (you don't need to follow him with the cursor once you are holding X)
At this point you'll get:
-- Go right, dialogue
-- Interact with the Blue Orb, dialogue
-- Right and right again, more dialogue
-- Hold R2 (R on Vita) to take the right tunnel
-- Go right, dialogue
At this point the trophy should unlock.