They would not let scooters on some of the small boats to FW and GF last trip and boy were they hot. During a rain out they did just close the boats. Apparently you can't take scooter on the small boats.
The small boats that travel from MK to the MK resorts don't take
ECVs or wheelchairs (unless the wheelchair can be folded). Those boats are pretty small and require a step down to get in.
If you are a GF, you would use the monorails to get to MK with an
ECV.
FW and Widerness Lodge are served by both the small boats and by bigger boats that are accessible to both wheelchairs and ECVs. The big and small boats alternate.
Walker is a service who will deliver to your resort or the parks. Check out the board DISabilities for a ton of scooter info!
Follow the link in my signature to either the disABILITIES Board or the disABILITIES FAQs thread. Post 2 of the disABILITIES FAQs thread has rental information, including links and contact information.
Although Walker apparently says their ECVs are waterproof, no one on the disABILITIES Board is aware of anything different about theirs compared to other companies that rent similar models. Walker does include a rain cover for the controls, which is very similar to a shower cap. The controls are the most important part yo keep from getting wet, do it's possible they consider it waterproof as long as you cover the controls.
Other things to consider -
Most of the ECVs have vinyl seats. Those are water repellent, but if you get it wet e ough, it's going to still get somewhat wet. A lot of people cover the ECV before sitting on it, either with a small poncho or a large plastic bag.
Then, they cover themselves with a poncho.
Stopping distance will be longer if the ground is wet and many of the surfaces will be somewhat slippery, affecting traction.
Beware of puddles. Some are much deeper then they look. Also be aware that your feet might get splashed a lot as you drive along.