Dip your toes in this water.

The Mid-Cayman Rise in the Caribbean has hydrothermal vents which spew out super-heated chemical-rich fluids into the cold depths, some 3 miles deep in places. But various life forms have adapted and thrived in the harsh conditions.
The Mid-Cayman Rise is part of the mid-ocean ridge mountain chain where volcanic eruptions creates new oceanic crust that pushes tectonic plates apart but scientists theorize that along some slow-spreading ridges the sea floor becomes unusually thin.  That allows water to percolate down to rocks heated by volcanism below. The water picks up chemicals from the rocks and re-circulate and vent at the sea floor.

One of the deepest sites, the Piccard vent field (3.1 miles deep) has fluids gushing from the vents at a temperature just above 400 degrees C (750dF) which are amongst the hottest vents known but  different mineral compositions of the seafloor here produce many kinds of vents. This area displays the broadest range of geological processes all active in a small area of seafloor. After the vents had been mapped the researchers used two devices to collect samples. 

The SUPR (SUspended Particulate Rosette) sampler is designed to gather dissolved and particulate samples from warm water plumes rising from the vents. The analyzed samples provide chemical, microbial and mineral composition of the plumes and what effects they have on the surrounding ocean water.
Also used are isobaric gas-tight samplers which collect high-temperature vent fluids and maintain them at the high pressure of the deep sea when they come to the surface.  They prevent compounds such as methane and hydrogen sulfide, which are liquid at high pressure from becoming gases as the sample is brought to the surface. The idea is to capture gasses before they can interract with the sea water.

Scientists found three species of shrimp, two of them new to science.  The females of one species were full of orange eggs. Usually there is only one species of shrimp and tubeworms and shrimp never colonise the same vent.
Tubeworms are usually found at hydrothermal vents in the Pacific Ocean and at cold seeps in the Atlantic, whereas shrimps dominate hydrothermal sites on the Mid-Atlantic Ridge.
Biologists now have to answer how both animals came together.

The remotely operated vehicle 'Jason' (barely visible at left of centre) found "furry walls" of microbial growth near the hydrothermal vents. The chemosynthetic microbes use chemicals from the hot waters for energy to produce their food which other animals consume. Since this is a place without light and without light, no plants, the microbes are the base of the ecosystem.
'Jason' also used its manipulator arm and vacuumed up snails, anemones, starfish,crabs, fish, shrimp, and tubeworms.

These researchers study this environment as they believe that life may have originated in the mineral and organic rich fluids at hydrothermal vents and hopefully they will recognize similar environments on other planets, if and when we find other planets beyond Earth.