Ok so I didn't found the glitch mentioned anywhere else so I'm going to post it here:

There's a glitch that makes the boat move in a straight line while maintaining speed. This means that the boat will keep moving fast without having to do anything.

To perform the glitch you need to:

1. Start the game (Pressing the "play" button or the "reset" button if you just finished a run).
2. Press the left and right arrow keys at the same time BEFORE the boat is at the starting line and keep them pressed. It's very precise, but if you do it correctly you'll see the boat doing the described glitch.
3. Still, keep them pressed: Don't let go of the arrow keys during the whole run. If you do the boat will turn left, right or simply stop.
4. Pray for good RNG. From here on all you have to do is keep pressing the arrow keys. The boat will go at a constant speed. If it hits an obstacle, it will lose speed. If it hits a checkpoint it will gain speed. More checkpoints = More speed = Better time. You just have to be lucky that in the straight line the boat is moving, there are a lot of checkpoints and the less amount of obstacles possible.

I hope this helps for anyone trying to get a better time. It's very simple to perform and will get you a good time really easily, though lower times depend heavily on RNG.

Cheers and good luck! ;)