Steps to Get Aquaman in Red Dead Redemption 2

Step 1

Firstly get Blackberry

Step 2

Then get Stringy Meat From Skinning Fox

Step 3

You can get stringy meat from raccoon as well.

Step 4

Or Get Stringy Meat From Coyote

Step 5

After that Go To Pier Near Water In Saint Denis

Step 6

Then go into the water by riding a horse.

Step 7

Change Into A Steerable Boat

Step 8

Press Triangle Button To Command Boat

Step 9

Hold X Button To Go Forward on the boat

Step 10

Then Steer Small Boat Next To the Big Boat

Step 11

Then press triangle to stop steering, once you get close to the big boat.

Step 12

If you're late then press square.

Step 13

Press X and Square To Run & Climb

Step 14

Now explore the ship.

Step 15

Press L1 + R1 + Select Bottom + R2 to Craft

Step 16

Press R1 To  Bait

Step 17

Now, don't craft any other, just wait there.

Step 18

After some time the ship will start sinking.

Step 19

Now, don't move and sink with the ship.

Step 20

You've to wait until the ship hits the sea floor.

Step 21

Now Hold O Button To Exit Craft Mode

Step 22

Now walk around the ship.

Step 23

Now you've to to dropdown next to the life boat.

Step 24

Now, you've become aquaman on the sea floor.

Step 25

Now Try Lasso On Sea Horses

Step 26

Try Water Silenced Gun (Water Gun)

Step 27

Lamp will not shine in the water.

Step 28

Now try to eat under water.

Step 29

Now try to see things underwater.

Step 30

Mark A Mexico Spot On Map

Step 31

Now Go Toward Mexico

Step 32

Don't Bump Into Sunk Ship

Step 33

Continue On To Mexico

Step 34

You Will Eventually Float Up

Step 35

Go to Craft Mode To Prevent Drowning

Step 36

Exit Craft Mode and Continue

Step 37

If you don't use craft mode then you'll drown.