As Brian's message indicates Ranger Tugs, when driven above displacement speeds are very sensitive to weight. We lost about a knot and a half on our R25SC when we loaded it for a typical 2 week trip. To maintain that performance: 1. Bottom stayed unpainted (boat is trailered) and gets waxed every year; 2. Packed carefully and tried not to bring stuff we would not use that trip and packed as lightly as possible. (Backack campers can carry what they need for a week on their backs and they don't bring the dutch oven that a camper in an RV might. I pack the boat somewhere in the middle - light weight cookware and dinner ware, etc., second anchor is a Fortress, bike on the roof weighs less than 20 lbs.) Spare prop would stay in the truck because I carried one for decades and never used it and the truck was typically within a hundred miles if I needed to go get it. The last leg of two week cruise would generally get us those early performance numbers because the refrigerator was getting empty and we tried to leave the lake with no more than a third of a tank of fuel for the day long trailer drive home. In my experience Ranger Tugs are not unique in this regard. Any boat's performance will be far more sensitive to bottom growth, even boats running more at displacement speeds.
(Brian, Thanks for the compliment. When we bought the F350 we had the bottom stripe put on it to match the blue hull on our R25. When we ordered the R29 in sand color we put the dark blue stripe on it to match the tow vehicle - it was a gamble that it would look decent and vinyl wrap is not permanent so we tried it. I think it works and it hides the scum line somewhat when the marina water we are in is not super clean.)
