I understand you don't want the hassle of 2 bags, but 2 bags are just much better than 1 bag. 1 bag will pull your boat to one side making boat control much harder. 2 bags will pull the same on each side of your boat making boat control much better. the 2 36" bags mentioned before will work good for you. that's what I use on my 21' glass boat with a 350 votec motor. gets me down to 1.5 with no problem. for trolling I think the trolling bags are better than drift socks. I have used both.