Rear Bumper Water Storage

Has anyone found a rear bumper that is capable of water storage? Saw Jeep Wranglers can store water in the rear bumper. Was wondering if anyone has made a custom bumper or seen any online that could store water with small modifications. Would be a plastic bumper. Was also looking at making one out of either ABS Plastic or marine Starboard plastic.

 

Any reason not to just go with a rear swingout and a couple Jerry cans? I did 2 jerry cans, a propane tank, and a case with a 12v pump and water heater. Made a great all in one system.

 

Sealant doesn't stick to starboard, I would not recommend it unless you're using a bladder. How much water do you need? Just get a waterport