We seem to get more and more of these posts- a Mainship Pilot Rum Runner? There are both 30 and a 34 Rum Runners. But the answer is the same: You will pick up maybe two feet of bridge clearance with the canvas lowered but the top of the windscreen will be the limiting height.
More about Mainship Pilot models:
Mainship started making the Pilot 30 in about 1998 in both hardtop and canvas top models. These were usually delivered with the Yanmar 220 hp 4LH engine. In 2002/3 they revised the hull using a tunnel above the prop a different layout and an interesting flip up V-Berth and also offered it with the Yanmar 315 hp 6LP engine, the better one IMO.
The Pilot 34 started in about 2001 with hardtop and canvas top models in both singles engine, the Yanmar 370 6LY and the twin Yanmar 220 hp 4LHs. It wasn't changed until about 2007/8 when it came out with square side windows rather than the swoopy curved ones on earlier models. I think the square ones look, well square.
Both the 30 and the 34 were offered with Rum Runner packages which among other things included air conditioning and a NextGen genset.
Late in its history Mainship changed the model name of the 30 to the 31. It used an entirely different layout with even funnier looking squared off windows.
Almost finally there was a Pilot 43, a big beast of a boat with twin Yanmar 370 or maybe 440 engines. Finally there was a model of the Pilot ?? built by Marlow after they bought Mainship.
So please be specific about which model you are asking about. Same with Mainship 34 fly bridge trawlers.
David