The run takes about 45-60 minutes from Renfrew at 20-ish knots. Best plan is to head to the western edge of the bank and look for the crowd of boats. Note that the fog is often present and very thick and assume you are completely invisible to the traffic around you.
Isn't a ThunderJet a river-oriented boat? I'd be careful taking it out onto the bank if that's the case -- be sure you know what the weather and ocean is going to do that day as you are a long way from shore if things go bad out there.