Because of the rave reviews, Im thinking of purchasing a BP and wings. Since I want to spend my money as efficiently as possible, Im trying to completely understand the issues, the first of which is buoyancy. Please let me know if my assumptions are corrected or where Im off course.
There are three key points to buoyancy:
1. Most important, because drowning is a permanent condition that prevents future diving, the amount of ditchable weight must be such that when dropped you are positively buoyant at the deepest depth, with a full tank (start of dive), no air in the BC (i.e. BC failure), and no air in the lungs (after exhalation and before the next breath).
2. Next most important, you must be able to achieve neutrally buoyancy at 15 feet (safety stop), with an empty tank (end of dive), with ditchable weight intact.
3. The amount of BC lift should be sufficient to make you positively buoyant at the deepest depth, with a full tank (start of dive), ditchable weight intact, and no air in the lungs (after exhalation and before the next breath).
Overall buoyancy at any given depth and time is the sum of the buoyancy of the diver and anything attached to the diver.
The buoyancy of some items remains constant while some are affected by depth (compressible items) and air consumption (air tank). Additionally the diver has control over the buoyancy of some items such as a BC and their selves (through breathing).
Buoyancy constant
Weights, back plates, mask, and flippers. These items are not compressible so the buoyancy is not affected by depth.
Buoyancy controllable
BC, dry suit, and to some extent the diver (through breathing)
Buoyancy affected by depth
Wet suit, dry suit, and BC. These are items that contain compressible air and buoyancy is decreased as depth (and pressure) increases.
Buoyancy affected by air consumption
Air tank. Buoyancy increases as air is consumed.
Any corrections, comments, or additions are appreciated.
Thanks,
Mike
There are three key points to buoyancy:
1. Most important, because drowning is a permanent condition that prevents future diving, the amount of ditchable weight must be such that when dropped you are positively buoyant at the deepest depth, with a full tank (start of dive), no air in the BC (i.e. BC failure), and no air in the lungs (after exhalation and before the next breath).
2. Next most important, you must be able to achieve neutrally buoyancy at 15 feet (safety stop), with an empty tank (end of dive), with ditchable weight intact.
3. The amount of BC lift should be sufficient to make you positively buoyant at the deepest depth, with a full tank (start of dive), ditchable weight intact, and no air in the lungs (after exhalation and before the next breath).
Overall buoyancy at any given depth and time is the sum of the buoyancy of the diver and anything attached to the diver.
The buoyancy of some items remains constant while some are affected by depth (compressible items) and air consumption (air tank). Additionally the diver has control over the buoyancy of some items such as a BC and their selves (through breathing).
Buoyancy constant
Weights, back plates, mask, and flippers. These items are not compressible so the buoyancy is not affected by depth.
Buoyancy controllable
BC, dry suit, and to some extent the diver (through breathing)
Buoyancy affected by depth
Wet suit, dry suit, and BC. These are items that contain compressible air and buoyancy is decreased as depth (and pressure) increases.
Buoyancy affected by air consumption
Air tank. Buoyancy increases as air is consumed.
Any corrections, comments, or additions are appreciated.
Thanks,
Mike
