trolling bags

Needed new trolling g bags to get down to "worm speed" so I called Amish outfitters for the beefy buggy bag.i told the owner frank, my boat was a 24ft. Sea ray that idled at 3.2 mph. He thought his 22 in. Bags would get me down to 1.5 mph at Rpms over an idle. The 22 in bags only got me down to 2 mph and when I called frank he put a larger set in the mail....trusting I would send him the old bags back and pay the difference. ....what great customer service. ...what does it take to get your boat down to worm speeds?