Samui Dive Supply

Samui Dive Supply
Our Showroom

Sunday, October 26, 2008

SELF CONTAINED UNDERWATER BREATHING APPARATUS (SCUBA) (PART 1)

Self Contained Underwater Breathing Apparatus (SCUBA) (Part 1)

A month or so ago, doesn’t time fly when you’re having fun, we said we will introduce SCUBA equipment to you, attempt to explain what it is and what it does for you.

As an introduction there are three basic types of SCUBA equipment:

Open Circuit

When you breath in you use a two stage regulator that provides gas at the ambient pressure from a tank of compressed gas usually at 200 bar. When you breath out through your regulator second stage the exhaled air vents into the water as bubbles. Your SCUBA equipment would also consist of a Buoyancy Control Device (BCD) and weight system. This is the system we will focus on in more detail in the next post. An example of an Open Circuit Regulator would be the Scubapro Mk25 1st Stage witha S600 2nd Stage.

Semi-Closed Rebreathers (SCRs)

When you breathe in, you breathe from a counter lung in your SCR. When you breathe out your exhaled air passes through a scrubber that removes the excess carbon dioxide in the exhaled air. This air then passes into the counter lung where it mixes with oxygen that is flowing at a continuous set flow rate to produce your breathing gas. Any excess gas in the counter lung is vented off as a small stream of bubbles. An example of a SCR would be the Drager Dolphin.

Closed Circuit Rebreathers (CCR’s)

When you breathe in, you breathe from a counter lung in your CCR. When you breathe out your exhaled air passes through a system that removes the waste carbon dioxide in the exhaled air and replaces consumed oxygen then it returns to the counter lung. There are no bubbles. An Example of a CCR would be the Pelagian from RebreatherLab.

Look out for the next post on Open Circuit SCUBA equipment.

Please feel free to comment on any posts in this blog.

To find out more about SCUBA equipment available from Samui Dive Supply please contact us for more information.