Batboat.....
BatMan's primary vehicle to travel in water..
Now its belong to Carl Johnson!
Have fun to use it as you travel across water and run from cops!
If you have problem to enter the Batboat, Here is a guide :
(detailed)
1.Swim to batboat side
2.Go to its rotor/engine/fan/whateveryoucallit
3.Press shift(Jump Button) while youre already there
4.If you managed to get to the top of batboat,You can now enter it with ease

(simple)
Jump to top of the batboat first to enter the batboat

Check my channel if you still cant get it
:)