Another title for this thread might be: "Don't believe the hype!"
Paint manufacturers market their more expensive
paints as "multi-season". Does that mean that the
paint will last from Spring until Summer, or through the Fall, or through next Fall? They seem to shy away from labeling these products as "multi-year" for good reason.
As Fstbttms so eloquently points out, these
paints only retard growth but do not eliminate it which helps to employ the many divers who clean boat bottoms. There is no panacea for bottom growth. Further, these 'highly engineered' paints are engineered to inhibit growth on the bottom
when it is in the water, not when it is sitting out in the air. So don't think that just because you are giving your anti-fouling paint a 'rest' by having it hauled out for a half a year that it is not also degrading in the air environment. The air environment may actually be harsher to your paint then the water environment.
Don't believe the hype.