Voyage of Despair: Secrets

The free perk

On Voyage of Despair, six fish hang around the ship, one at a time: the next one appears when the last one is picked up. Shoot each one down, then pick it up.

Forecastle fish

Under the white canopy.

Poop Deck fish

On the middle rope.

Aft Decks fish

On the ropes on the left side.

Mid Deck fish

By the exhaust pipe.

Boiler Room fish

Above the portal.

The sixth fish

The guides do not agree: under the catwalk of the Promenade Starboard Deck, or above the Engine Room, shot down from the Galley.

The six fish go on the box with a fish on it, on the Sun Deck. It drops a perk that gives a fifth perk.

Drowning

Shooting four coins plays Drowning, sung by Malukah:

Forecastle coin

On the side of a box under the stairs, near the Danu altar.

Lower Grand Staircase coin

Above the Pack-a-Punch pedestal.

Sun Deck coin

On a lifeboat.

Poop Deck coin

Near the Pack-a-Punch pedestal.

The special weapon fire sale

Pick up three sheets of music: in the revolving door of the Promenade Starboard Deck, on a table of the Dining Hall near the Lower Grand Staircase, and on a bench of the Promenade Port Deck.
Put them on three pianos: on the Upper Grand Staircase by the door to the Bridge, on the Lower Grand Staircase near the SwordFish, and in the Dining Hall near the doors to the Lower Grand Staircase.
Hit each piano with the special weapon until it glows blue. A fire sale follows, during which the Mystery Box only gives special weapons.

Low gravity

A moustache on the Promenade Starboard Deck, a crown on a smokestack seen from the Bridge and a trident in the Engine Room, each one freed with an explosion or a shot, go on the body hanging on a wall of the Galley. From the next round, the zombies move as if in low gravity.

The hourglass

Shooting the mesh of the small white smokestacks of the Boat Deck with a weapon packed twice brings out an hourglass. Followed from portal to portal down to the Poop Deck, it makes the first three fast travels of each round free.

In the First Room

Only two of these secrets touch the Forecastle: one fish of the free perk and one coin of Drowning. Every other part is behind doors, and the free perk needs all six fish.