The main premise behind SOAK is that it aims to remove some of the guilt which may result from being a regular visitor to resource-heavy spas or bathhouses, by using renewable energy sources and recycled shipping containers.
SOAK looks like it will be pretty well stocked in bathing facilities, with a couple of cold plunge buckets, a shower, and a solarium. It's not clear what the capacity would be (presumably not very high), but a small physical footprint would also make sustainable energy more practicable.
The concept calls for 10 percent of SOAK's water to derive from collected rainwater, while its designers state that all required electricity would come from solar power thanks to photovoltaic cells on the roof. Finally, grey water will also be reused, either for the small garden or recycled elsewhere.
If you'd like to get in on the action, SOAK's aptly-named creator Nell Waters has launched a Kickstarter campaign, which still has some way to run. If successful, Waters plans to install a working prototype unit in San Francisco, with other SOAK units eventually rolled out to Brooklyn and Portland.
The video below contains more details.