I'm guessing that JNB put the same pintle hooks on your houseboat as they put on ours back in 2020. Here's the instructions and photos that were sent out to the owners of our houseboat on how to operate them:
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Instructions for us of the pintle hooks on the attaching the houseboat to the buoy.
- detach stainless steel cotter pin.
- pull down the locking latch located back side of the pintle hook, this will open the latch.
- place the "eye" of the cable through pintle hook.
- lift the locking latch, this will close the pintle hook and secure the cable.
- replace the stainless steel cotter pin.
- houseboat is now safety secured to the buoy.
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Make sure when you are attaching the cable to the houseboat that you
lift the locking latch before you put in the cotter pin. I may or may not have first hand experience knowing what happens when you don't do this and seeing photos on Facebook of our houseboat pushed up against the breakwater the day after when I was already home
For our houseboat, there are pintel hooks on each side of the houseboat (port and starboard). There is a cable that goes from each pintel hook that attaches to the buoy. The cables attach to the center ring on the buoy with large marine shackles similar to those in this link-
Galvanized Screw Pin Anchor Shackle
e-rigging.com
I'm unsure of the size that you will need and would assume you would need at least 2 (one for each cable) and a couple extra spares in case you ever have any issues or lose one. I would contact executive services again and see what size shackles they recommend (I'm honestly shocked they don't provide those for you). We leave the cables permanently attached to the buoy and just disconnect them from the pintel hooks when we take it off for the week.