I consider myself a fairly strong woman and I also found it a NIGHTMARE to pump my iSUP.
I eventually caved and ordered this portable pump and it’s made the process SO MUCH EASIER: https://www.amazon.com/SereneLife-Electric-SUP-Pump-Compressor/dp/B07V9WCBN7/ref=mp_s_a_1_9?crid=VJMO7FRA7CCQ&keywords=portable+pump+isup&qid=1659494948&sprefix=portable+pump+isup%2Caps%2C98&sr=8-9
I’ve only used it to pump up these boards but it seems pretty simple and straightforward. It’s a sea gods branded version of this pump you can get on Amazon. https://www.amazon.com/SereneLife-Electric-SUP-Pump-Compressor/dp/B07V9WCBN7 We will see how it does out in the wild.
So this one is actually has a stand alone battery in it. https://www.amazon.com/gp/product/B07V9WCBN7/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
I don't have my paddleboard yet (arrives tomorrow) but I used this unit to inflate my neighbors Costco Hyperlite Admiral board that is 11 feet long up to 15 psi and then deflated it empty again and it used about 20% of the battery to do both. It does come with various sealing rings to fit different board connections.
I would just invest in one of these: https://www.amazon.com/gp/product/B07V9WCBN7/ref=ppx\_yo\_dt\_b\_asin\_title\_o03\_s00?ie=UTF8&psc=1
if you go the electric/battery pump route, this one is compact and inflates at least two iSups on one charge up to 16 PSI.
We use the one below - it's rechargeable so we can take it anywhere, but it can also be used plugged into a vehicle. Set the PSI and it shuts off automatically once it gets there. It's awesome, it does two SUPs and a couple of kayaks no problem - but it does get hot. The SUPs take longer and it's pretty loud but it's a ton better than all that manual pumping.
Electric SUP Air Pump Compressor - 16PSI Rechargeable SUP Pump 12V Stand Up Paddle Board Electric Pump Inflator/Deflator - Portable Air Compressor for SUP, Boat, Pool Inflatables - Serenelife SLPUMP50
https://www.amazon.com/gp/product/B07V9WCBN7/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1