I have a 21 foot Nautic Star bay boat. I have two four holder spider lock rod holders in front and two in back. My home lake has a 3 pole limit per angler. With myself and one other, I run two rods off the front, one on each side. I run four off back, two off each side. I run basically the same set up with three in the boat especially if they are not experienced long liners. With experienced guys I add another rod to each side on the back. Mrdux is giving you some good info. Follow his advice and you will do well.