If you are out on the water and run out of gas dont panic, if you have a partner with you have them lay across the back deck and pump the primer buld. You will be able to get the motor fired back up and run. This will get you a couple of miles closer to the ramp if you'll just get the boat up on plane and cruise along. Your partner will look like a idiot laying back there pumping that bulb while you are running but it will work. Just make sure he wears his PFD!
If no partner I would imagine that you could pump it, start the motor and go a little ways until it dies, just keep donig it over and over getting a little closer to the ramp each time. Could save you some paddling.