For the environmentally conscious
Some good points about hovercraft
We do not pump oil and petrol fumes into the water.
We do not churn up mud
We do not cut and damage underwater plants and marine life.
We do not make underwater noise.
We cannot drive over reeds or even tall grass.
We leave less of a footprint than a human being.  The average craft has a footprint pressure that is less than a 100th that of a human.
The skirts are soft and flexible, they do very little damage and do not disturb marine life.
Even though fan noise is our real problem, it leaves nothing behind.
You can ride over a person in the water without injuring him.