Is there any way (using console or otherwise) to increase the speed of the boats in the game it's just too slow for me (a lot of stuff in Skellige is accessible by boat only) .
Similar to horses, double tapping the acceleration key (A on the controller) does make the boat go faster. This is not indicated in the UI, so it's easy to miss.
But by far the quickest way is to use harbors, they're fast travel points for boats. They are only visible on the map when you're at the helm of a boat. Just open the map while you're on a boat and look for anchor symbols.
Merchants on Skellige also sell maps that reveal fast travel points on specific islands. Those will remove the need for a first boat trip there.