A golf cart can tow a jet ski.
They can tow an average of 1000 lbs of cargo. A jet ski weighs about 700 lbs.
Here is the towing capacity of a few models:
EZ GO Express S4 – 800 lbs
Cushman Hauler 800 – 900 lbs
Polaris Industry Ranger 500 – 1500 lbs
Titan HD 36 Volt – 4600 lbs
They can tow 800 to 5k lbs depending on make and model. Check with dealer or manufacturer for exact capacity.
Here is a video of a golf cart towing a jet ski out of the water proving that it can be done: