Get some Scuba lessons and learn to do it safely.
Breathing compressed air without the training is very dangerous, even in the shallow water. Additionally workshop type compressers are oil lubricated and have no filtration or drying for the air. While such a rig could be made, it would provide air with oil droplets, whatever junk is floating around the compresser such as exhaust from next boat over idling at the dock and water condensation in the hoses to give you problems. All in all, it's a bad idea if you value your health.