The Y-40 Deep Joy is the worlds deepest pool. Y-40 is projected by Architect Emanuele Boaretto and supported by the “Boaretto Group Hotel and Resort”. The name Y-40 is inspired by mathematical symbols. “Y” is the ordinate axis of the Cartesian system and “–40” means the world's record depth or our pool- that is 40 meters underground. (Photo by Courtesy Y40 Deep Joy)

Marcus Semien #2 of the Texas Rangers is doused with sports drink after the game against the Seattle Mariners at Globe Life Field on June 03, 2023 in Arlington, Texas. (Photo by Sam Hodde/Getty Images)

Filipino mermaid swimming teacher Genevieve Reyes (C) has her tail adjusted by students during a lesson by the Philippines Mermaid Swimming Academy in a private swimming pool in Makati, Manila, Philippines, 15 June 2013. The Philippine Mermaid Swimming Academy (PMSA) was created in 2012 in Boracay by Normeth Preglo of The Philippines and US swimming instructor Djuna Rocha. The swimming lessons were brought to Manila in April 2013. The price for a two-hour class is 37 US dollars. (Photo by Dennis M. Sabangan/EPA)

Girls prepare to take part in a mermaid lesson in Rio de Janeiro, Brazil May 28, 2017. Women in Brazil are not unique in their affinity for mermaiding. Classes are held as far away as Texas and some folks wonder if mermaiding will be the next fitness craze. (Photo by Pilar Olivares/Reuters)

A French bulldog named Rocket takes part in the annual Surf Dog Surf-A-Thon in Del Mar, California, on Sunday, September 7, 2025. (Photo by K.C. Alfred/The San Diego Union-Tribune/Getty Images)

A swimmer reacts after finishing his competition in a pool carved into thick ice covering the Songhua River during the Harbin Ice Swimming Competition in the northern city of Harbin, Heilongjiang province January 5, 2015. The swimming competition was held on the official launch day of the Harbin International Ice and Snow Sculpture Festival. (Photo by Kim Kyung-Hoon/Reuters)

Maddy Ashford and fellow wrestler and trainer Paul Sargeant at a training session at The Lancashire Wrestling Federation in Chorley, UK on October 9, 2024. Maddy Ashford is still at school and is a wrestler taking the ring by storm and has competed in 40 WWE-style competitions in just 10 months. (Photo by William Lailey/South West News Service)

Grey seals show their playful side while swimming off the English coast, UK in the last decade of May 2025. (Photo by Brian Matthews/Solent News)