Sarah and Sam spend some time talking about how heavy water is, why that is important for ocean circulation, and the abject horror of barotrauma.

Resources:

https://oceanservice.noaa.gov/facts/pressure.html

http://glossary.ametsoc.org/wiki/Decibar

http://oceanmotion.org/html/background/ocean-in-motion.htm

https://en.wikipedia.org/wiki/Ocean_current#/media/File:Ocean_currents_1943_(borderless)3.png

https://adventure.howstuffworks.com/outdoor-activities/water-sports/freediving.htm

https://www.youtube.com/watch?v=_cj8AtODiHc

https://wildlife.ca.gov/Conservation/Marine/Groundfish/Barotrauma

https://www.smithsonianmag.com/science-nature/behold-the-blobfish-180956967/

https://www.smithsonianmag.com/smart-news/in-defense-of-the-blobfish-why-the-worlds-ugliest-animal-isnt-as-ugly-as-you-think-it-is-6676336/

https://www.health.harvard.edu/a_to_z/decompression-sickness-a-to-z

https://www.sciencefriday.com/educational-resources/high-pressure-in-the-deep-ocean/

https://en.wikipedia.org/wiki/Byford_Dolphin#Diving_bell_accident