Boat cup holder

Cup holder for a (sail-)boat or anywhere that has a 25mm or 30mm vertical tube/pipe/rod for attaching the cup holder. Included versions for 25mm and 30mm mounting options.
Print with (preferrably UV-resistant) flexible TPU / TPE with 20-30% infill.
Has channels for zip-ties if more secure mounting is required, but holds very well without as long as the material is not too soft.