Have you ever heard of Rhodes lifters? This brand had a fast bleed also.The theory is, when the engine is at low rpm these lifters bleed off oil and do not fully pump up.This is suppose to make a difference in idle and allow a big hydraulic cam act more civilized by affecting the lift and duration.When rpm picks up oil pressure increases and pumps more oil into the lifter than what is bled off.This lifter now acts like its solid and performs as the cam mfgr designed.I recall the rhodes had a "tick"at idle.I don't think you need these type for jet boat use.I think the high energy lifters are just high quality standard hydraulic lifters.Call Comp Cams for a recommendation or try clay smith.