While being launched at Yarmouth boat launch Vessel A struck Vessel B while it (vessel B) was tied to the dock.  Operator A stated that the throttle on vessel A was stuck wide open when the motor was started.  Vessel A made two circles with the throttle stuck open almost ejecting Operator A.  Vessel A struck Vessel B at a 90degree angle on  the portside rubrail of Vessel B and then continued to make contact down to portside of vessel B towards the stern.
Yarmouth                      