Wonder if your boat is a bit water logged? If the boat is heavier due to a leak in the hull and it has soaked up water in the foam.
This why I would want to see pictures of the boat, or at least year and model. If it's a low transom height and has scuppers for draining water in and out I would say it's pretty normal. If it's a high transom and water is coming in then something is not right. It could very well be the boat is carrying some extra weight around.