Wolfeboro Corinthian Yacht Club rents a 24ft tritoon with a 250hp engine -
http://www.wcycnh.com/pontoon-rentals.html
I believe Goodhue Hawkins has some Sanpan tritoons w/150hp engines.
Here's a list of all the boat rental outfits in the lakes region -
https://www.facebook.com/notes/boat-...18744308304430