[Peter Smith]

I'm a long-time Mac-head but a complete novice at onboard use: we're just starting out with a new boat, cruising in NC, and I've equipped my iBook G3 with GPSNavX and a GlobalSat GPS sensor with USB connection. The last item, power supply, seems to be the hardest to solve. Is there any reason I can't run the iBook from two 12-Volt batteries in series, producing 24 volts? If there is a problem, it must be the need for a power-input plug; is there anywhere I can purchase a coaxial plug that will fit my iBook and can be wired to two 12-Volt marine batteries in series? (If this IS possible, surely it would be simpler than using a cig-lighter outlet, an inverter, and the iBook's 120-to-24 volt adapter, or using the expensive 12-volt-to-24-volt adapters available from Germany?)
Any advice will be much appreciated!
Peter Smith