Personal watercraft have a jet drive system which requires some
extra precautions to avoid spreading harmful aquatic exotic
species. A pump pulls water in through an opening under the
craft, and the impeller (an internal propeller) forces water
out, moving the craft forward. Exotic species can easily get
lodged in the jet drive system and get transported if the
watercraft is taken from one water body to another. A small
piece of Eurasian watermilfoil, or other harmful exotic species,
caught in the impeller can infest a new lake or river. Zebra
mussels could live in excess water in the jet drive and spread
to another body of water. In the water: Avoid running the engine
through aquatic plants near the boat access. After the engine
has stopped, turn the watercraft over while still in the water
and pull plants from the water-intake area (this may be easier
than crawling under the watercraft while trailered to check for
plants). Check the edges of the grate over the water-intake
area. Push or winch the watercraft