The compressor (e.g. Ryobi One+ P731) adapter for the Bravo (ver 4, used by many isup manufacture e.g. Jobe) hand pump tube.
A thick isup board takes a quite long to fill up with the hand pump even with reasonable two function pump.
The P18I compressor has high volume (low pressure) and high pressure (low volume) functions. The high volume mode gives ~300l/min so SUP board fills up in no time. Thought, the internal pressure is limited on air mattress level.
The benefit of this solution is that no extra sealing are needed because the original HR connector & air hose is used. The adapter comes on the hand pump end of the hose.
Note that the HR connector opens the isup's valve, before turning the compressor off unplug HR connector. Connect the hose to the high pressure pump and then back to SUP's valve.
There is a challenge to get FDM printed parts air thigh. A small compressor has limited high pressure output volume so even tiny imperfection will make the difference. Out from the printer I manage to get up to 3.5 psi pressure before there was too much leakage via invisible hole. The inside surface epoxy varnish makes the difference :-).
The high pressure compression takes quite a long time (especially for 6" thick board) so if you are in hurry use the hand pump to finish the job.