Rental-boat cup holder or portable resting base?
Choose by attachment and motion.
Existing boat holders
Use the operator’s intended arrangement and follow their instructions. Do not alter mounts to accommodate a drink without permission.
Removable accessories
A removable clamp or suction attachment still needs compatibility and approval.
Steadi at a stop
Steadi widens the base of a compatible container on a supported surface. It does not anchor the drink against wake or boat movement.