Nitro Rc Boats Motors

what’s the biggest radio control 2-stroke marine engine & where can i get one bigger than 26cc?

my rc boat needs more power than it’s current 26cc motor.. Is a larger one (say around 40-60cc) available? Must run on petrol not nitro fuel.

http://www.marinespecialties-rc.com/z23pricelist1024.htm or http://www.dynamiterc.com/Products/Default.aspx?ProdID=DYN6450
Vortex 46 Nitro Powered RC Boat