Well, to start the boat is under powered. You probably would have noticed that on the sea trial. I'm not sure why manufacturers under power their boats (at the base model), but they do. - Saves a few $$$ on the selling price, I suppose.
The dry weight of the boat is spec'd at 6,000 lbs. and the engine is 300 HP, which is good for a 5.7 L
The boat is fairly light for its length, but still a single 5.7 L engine vs. a 27-28 foot boat is out-matched.
A couple of things you could do . . .
1) See if you can verify the actual weight of the boat (removing all the gear and having as little fuel/water in it as possible). Head off to the truck or waste recycling scales. If the weight proves to be a lot more than the spec'd "dry weight" then you may have to look into what may be causing that.
2) Go down to a 19" or 20" pitch propeller set and see if that improves things. (Is it a dual prop or single prop outdrive?)
3) Remove any excessive gear from the boat, or possibly locate more of the gear forward.