Sand and gravel migrate both down into the river/lake and into the boat.
I'll take grass any day, and it is self-healing.

Padeen


"Marsh Jones" wrote in message
...
Sand or pea gravel. Sand is probably the friendliest non-slip medium
you can find - soft enough not to scratch the bejeebus out of kevlar and
carbon boats, and easy on feet trying to get in and out of the boat.
Ideally, you might even have two 'steepnesses' - one for canoes and
other floating launch boats, and the other for seal launching from the
shore. Great to see someone considering something other than a 2'high
dock:-)