I made this mod with CLS-Sailboat. I removed heavy code block and enhanced many features.

New Features

Player can easily control boat with keyboards and look around freely while sailing.
Player can continue sailing even though new cell has different water height.
Logic for collision on ground is enhanced, so player can easily escape from collision.
Weather fluctuation and screen transaction when boat is started or stopped is removed.
Boat's poly object is modified to allow smooth starting.
Convenitent menu commands are provided.
Player can pick up one player horse and four companions.
Travel time to another cities is recalculated properly.
Dissipation of boat resources usage is fixed. This is internal problem, so user can't recognize.
Provide additional convenient camera mod for easy sailing.


You can buy a sailboat at IC Market, Jensines Good as New Merchandise and find at Water Front beach.
Sailboat position is well adjusted if you are using better cities.


Sailboat Controls

Forward Key (default = w): Move forward.
Backward Key (default = s): Move backward.
Left Key (default = a): Turn left.
Right Key (default = d): Turn Right.
Enter Key: Stop. Hold down until stopped.

If you want change Enter Key, open console and type,

set sbStopKey to Keycode

Keycode should be digit. Do not use hex.
You can also check exact key code at
http://cs.elderscrolls.com/constwiki/index.php/IsKeyPressed3

Please read attached manual for details.

Credit.
I'm greatly thanks for original author CLShade.
http://www.tesnexus.com/downloads/file.php?id=17150.
(If there is problem, I will remove this file.)