A problem I recently convinced myself that I had is, after a dive in the Puget Sound, I had no ready way to wash off my gear. Scuba gear is stupid expensive, and saltwater is just about the most hateful natural substance there is when it comes to playing nice around manmade things. So it's important to rinse things with freshwater ASAP before the saltwater has a chance to dry and leave wonderful deposits of salt everywhere. Those deposits can really do fun things to thin rubber seals (like flappy one-way seals on drysuit valves!).

In the colder months, it's not as big of a rush, as typically the gear won't dry for a while given the cold, but in warmer months, or generally with the year-round issue where once I get home, I don't necessarily want to spend 30 minutes in the bathroom washing that stuff off, a way to wash gear right as I get out of the water would be cool. Even better would be to have hot water, as it's typically a lot more effective to dissolve things. Just because of excess, I really wanted this to be able to provide anyone who also wanted to use it with the opportunity to do so, which meant some consideration of capacity.

Getting everything together

The first step was finding a water container. The ubiquitous water storage solution is the venerable IBC tote. These are in a few different quantities, but the most common are 275 gallon and 300-something. If you keep your eye on auction sites, these arent hard to get for 20-35 a piece, though you'll typically need to clean them and likely wont be drinking water from them ever. The world of craigslist/FB marketplace is once again one detached from reality where people have these up for sale for as little as 60, but typically closer to 100 per... even for an absolutely beat and greasy tote. By my luck, I linked up with a guy at a facility that gets 30-40 of these totes in a month full of a midly toxic chemical, and due to a variety of circumstances, are cheaper for him to get rid of than return. He was offering a nice price of 40 per for effectively brand new totes, with a caveat that they still had a few gallons of nasty chemical in them. That is something I can deal with, so i picked a couple up.

After responsibly cleaning out the totes and making sure they could at least hold water fit for contact with human skin, I'd moved to the next problem... The water. The totes I grabbed were 275 gallons, and realistically I would be dumping a lot of this water whenever I wanted to move the tote out of the truck... So I had a particular problem with filling it from a garden hose. And then I remembered -- The crawlspace of my house has a sump pit that in the rainy months easily pumps out 500 gallons a day... That is not an exaggeration. It's a river down there. I'd built a massive sump pit years ago, but one not-to-code thing done by the previous owner is plumbing the discharge of that into my home's waste/sewer line.

So I'd figured I could solve two problems at once here and re-plumb that to discharge outside the house, and make that a removable connection that I could attach a hose to and fill the tank with. Thankfully the truck is parked below where the top of the tank is just about below the connection point, so any head lift isn't much of a factor. As far as the cleanliness of the water goes, it is surprisingly clean, coming from the equivalent of an underground spring. I'd taken a look at the sample under a microscope and while there was some trace organic debris here and there, there were no living microorganisms that I could find! Still not drinking water, but I'd be perfectly fine showering with it.

I'd put a camlock connection there, and made sure to add a cheater valve above to prevent the hose from pulling a huge vaccuum when the pump stopped and the discharge was downhill. White paint was necessary here as this is a very high-sun spot, and ABS really doesn't like the sun.

With my water sourcing problem solved, it was really just assembling adult legos. I'd grabbed a 12v on demand pump, as well as a portable tankless propane water heater, and used the existing sheet aluminum plate on the tote as a mounting surface, using self-tapping screws to reinforce/affix it to the tote's cage. I made a long pigtail to connect the pump to the truck's 7 pin trailer connection. This will provide 12v when the truck is in accessory mode.

From there, is after a dive walk back, open up the driver door and put the truck into accessory mode. This starts delivering power to the 12v pump and pressurizes the system (all valves are left open). The shower head has an attached on-off valve that is kept off. I'd then walk to the shower head, grab it off the mount and turn it on. The water now flowing activates the water heater, which sparks the burners and starts heating the water which gets 'oh-shit-that-burns' hot in a handful of seconds. The flow rate of the system is about 1.5 gallons per minute. Given that math, with a full 275 gallons and maybe 250 being usable, that's about 2.7 hours of continuous runtime for water alone. If my math is right for the propane tank, that thing can keep going for about 12 hours on a full 20lb tank. Hot water for everyone!

When I'm done with it, I can drain the tank out, disconnect the propane tank, tuck the power cable in somewhere and lift it out with the crane or excavator. Success!