There is a wide mouthed grab hook that fits onto a normal boathook in Force 4's catalogue, I think about £35. This is similar to the ones that have been around for years for picking up buoys/rings but is big enough to hook onto the end 'D' rings on French pontoons. We bought a pair of them in France (for not much over the price of one from Force 4) and find them very useful over there, where there are no cleats on the fingers, although we use them as quick clip ons having stepped ashore because our topsides are not that high. We also use them for grabbing buoy rings from the boathook so they would work like that in your berth probably. Note that these cannot be remotely released like the Bosco thingy.
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