You can take a trip down the Kenai River (mellow ride) or Matanuska (adventurous). If you do the Matanuska you can take a short easy hike right up to and on top of the glacier. NOVA river runners is an experienced outfit up there.

Another place not mentioned if you don't mind a short drive is Homer. The bay is spectacular if you hit the weather right. Take a water taxi over to Halibut Cove and have lunch at the Saltry restaurant. That is if it still opens this summer after the owner was charged with harassing a seaplane pilot.