JMods have said they didn't design Sailing as a quick means of travel around the world. That is pretty disappointing though. It just goes against the idea of what most people have of Sailing. Especially with how much charting reinforced exploration and travel.
Now imagine you could go to any port or mooring point where your boat is docked and fast travel to any other port or mooring point you have unlocked. It gives more meaningful unlocks with Sailing level ups and helps the skill integrate it into the rest of the game. It also would reduce the need for other types of travel to islands (looking at you Spirit Tree on Laguna Aurorae). Fast travel would make port tasks OP, but that could easily be mitigated by losing any cargo if you fast travel. It should give a menial amount of xp on fast travel too, like navigating an agility obstacle.
I don't see how this could be OP, but if it is then there are easy ways to curb it some. Like requiring crew with a certain Helmsmanship level aboard or increasing the time the fast travel takes.
This could be easily implemented by adding a right click option to docking points for fast travel. It would bring up a menu similar to charters letting you select your viable destinations. Even better would be something like the Runelite plugins Nexus Menu Map or Teleport Maps.