Motorboats have existed in Fortnite since the inaugural season of Chapter 2 and the new map. These vehicles were then the only means of mobility on the battle royale, allowing you to move very quickly on seas and rivers, but also on land, via the boost of the engine. Some players even used other ways to increase the speed of their ship, either by using the rockets on the boat or by hitting it with a couple of picks to give it a boost.
These two speed boost features were actually glitches, so the developers sneaked them out via update 11.50 — though not mentioned in the patch note. French dataminer Yanteh was one of the first to point this secret patch in the game files.
Indirectly, motorboats are nerfed. It will become even more difficult to make a rotation thanks to it if you wish to take the land. In itself, this fix is legitimate because the two boosts tricks weren't very logical or aesthetic — firing rockets on your own boat is a bit against the normal use of the weapon. However, it further decreases mobility in Chapter 2... Of course, the return of the Launch Pad somewhat compensates for this lack of mobility, but it's a meager compensation — and a bit late!
You've been warned: the motorboat became really slow once it left water.