I don't do a lot of boat fishing, but when I do I use a 10 foot #4 rod with a GT90 #5 line and fish, as you do, around 10-15 yards from the boat as it drifts.
I like the GT line because everything is nicely tapered and there is no need to "get the head" out the tip ring etc. it just casts lovely and loads the rod well.
It also allows a roll cast if the wind is being a bit tricky.
I also use this set up in a tube as well.
Other may have a different opinion though