This guy is floating his RPi5 on water while it is validating the bitcoin blockchain under 4 hours.
Discussion
Here the links for the UPS hat and batteries if you'd like to build a Floating Node for the lulz :
https://www.amazon.com/Geekworm-X1202-Raspberry-Shutdown-Detection/dp/B0CRZ4ZXQW
https://www.amazon.com/SOOCOOL-Authentic-Samsung30Q-3000mAh-Rechargeable/dp/B0BNLPWKXR