As reported to Fergus the cable and crocodile clips are not appropriate, my batteries are under the berths and in the engine compartment. I need approx 10m of cable to get to the foredeck from the batteries. Take a look at CTECK MXS5, and look at the extension leads and the permanent wiring they provide, I think it would be much more suitable. I have this for my car.
PS not used your pump yet .
Small in size, but inflates the boat quite fast. Worth while purchase.