Are you pumping and pumping, your SUP board is holding air, and yet... the gauge does not seem to be registering the PSI?
The gauge will not register until the board is at around 7-8 PSI. Even though it seems rigid, it will still be able to get more pressure. Trust us, there is no way to over-inflate or damage the board with a hand pump!
Just keep pumping until it registers. You should feel heavy resistance as you push down for about 20-30 pumps. After that the pressure should show.
We recommend riding the board at 10-15 PSI. The board will perform at its best at 15 PSI.