Drink Holder With Suction Cup

I created this drink holder because I always spill mine when I go fishing in a boat. We rent the boat, so I needed a non-permanent solution. I used these suction cups with embedded rods from Amazon, but any other model with similar dimensions (see attached JPG file) should also work : https://www.amazon.ca/dp/B0BXGWJW2X?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1. I added a threaded ring that you can screw down once the suction cup has been pushed down, to add stiffness to the holder. Instructions:Insert the threaded rod through the drink holder and hand tight the nut.Screw upward the threaded ring on the drink holder, a little higher than the bottom of the holder.Push down the holder so the suction cup gets compressed and sticks to the surface.Screw downward the threaded ring to add stability.To remove, either slide the holder to the closest edge of the surface it is on, or screw upward the threaded ring and slide a finger in one of the three openings at the bottom of the holder to lift a