There are quite a few yachts in the 50'-150' size range, maybe even larger, that use waterjet drives. Lars(AMG) tells me that the Hamilton and KaMeWa drives used on yachts have the buckets for reverse just like the smaller jet drives. I would think the Captains of those yachts would use that feature mainly for docking. Can you imagine what destruction would occur inside the yacht at higher speeds if the buckets were brought down quickly??