This is an underwater Earthcache. It is possible to solve it without scuba gear - snorkeling will do the job - but you'll definitely need to swim. It is not possible to solve it from the beach.
Champagne Reef is named for the champagne-like bubbling waters rising from thermal springs on the ocean floor. Underwater you'll see a lot of geological features and you can even find the remains of the 17th century Spanish shipwreck.
The term "geothermal" is used to refer to the heat that comes from the interior of the earth. All over the world you can see evidence of geothermal activity: Where this heat rises to the surface. The most striking of which are volcanoes. Hot lava (molten rock) bursts it's way out of the ground and can make for a amazing sight. But besides volcanoes, lava and ash, the internal heat of the earth makes its way to the surface in other unique ways through geysers, fumaroles, hot springs and mudpots.
A lot of the geothermal features are very colorful. The reason for these colors are substances found in the water present in these features and the color is a very good indicator of what these substances are. If a spring has a red color to it, most likely it is caused by a large amount of iron. If it is yellow, it is probably due to the presence of sulfur as hydrogen sulfide readily oxidizes to sulfuric acid and native sulfur. Pinks and whites are often caused by the presence of calcium.
A fumarole (or fumerole – the word ultimately comes from the Latin fumus, "smoke") is an opening in a planet's crust which emits steam and gases such as carbon dioxide, sulfur dioxide, hydrogen chloride, and hydrogen sulfide. The steam forms when superheated water condenses as its pressure drops when it emerges from the ground. The name solfatara (from the Italian solfo, "sulfur") is given to fumaroles that emit sulfurous gases.
Fumaroles may occur along tiny cracks, along long fissure, or in chaotic clusters or fields. They also occur on the surface of lava or pyroclastic flows. A fumarole field is an area of thermal springs and gas vents where shallow magma or hot igneous rocks release gases or interact with groundwater. When they occur in freezing environments, fumaroles may cause fumarolic ice towers.
A hydrothermal vent is a fissure on the seafloor from which geothermally heated water issues. Hydrothermal vents are commonly found near volcanically active places, areas where tectonic plates are moving apart at spreading centers, ocean basins, and hotspots. Hydrothermal deposits are rocks and mineral ore deposits formed by the action of hydrothermal vents.
Hydrothermal vents exist because the earth is both geologically active and has large amounts of water on its surface and within its crust. Under the sea, hydrothermal vents may form features called black smokers or white smokers. Relative to the majority of the deep sea, the areas around submarine hydrothermal vents are biologically more productive, often hosting complex communities fueled by the chemicals dissolved in the vent fluids. Chemosynthetic bacteria and archaea form the base of the food chain, supporting diverse organisms, including giant tube worms, clams, limpets and shrimp.
Logging this Earthcache
To log this earthcache, please answer the following questions and send them to me (Email or Messagecenter):
1. What do you see when diving at the coordinates? A hydrothermal vent, a fumarole or both? Explain the answer in your own words.
2. How big are the bubbles approx.? Why do you think, do they have this size and are not bigger or smaller? Give reasons for your answer.
3. Have a look at the area surrounding the origin of the bubbles? What color is it? What do you think is the reason for this color? Explain in your own words.
4. Optional but greatly appreciated: Take a photo of yourself with the bubbles and post with your log.
You can log immediately. You don't have to wait for an answer. Please send the answers in English or German.
Wikipedia: Hydrothermal vent