The Dive Otter

Proper Weight

Discussions on the topic by FlowState Divers | DoktorBEN | UTD

WARNING-WARNING-WARNING
THIS DISCUSSION IS BY A RECREATIONAL DIVER FOR RECREATIONAL DIVING WITHIN RECREATIONAL LIMITS

Buoyancy basics

Buoyancy, when you strip away the scientific discussions that involve the concepts of water density and displacement (Archimedes' Principle) and gravity and volume and upward force and temperature and humidity and who knows what else, is at the end of the day about managing weight. What makes it difficult underwater is that the variables I mentioned above change minute by minute...literally. There is no point in understanding the nuances of the science until you have the proper weight for TWO situations where buoyancy is critical. Ignore everything else at the beginning. Yes everything, ignore your breathing, ignore placement, ignore ditchable or not ditchable, ignore it all. You need two points and only two points to get started:

1. The minimum weight you need to descend at the beginning of your dive
2. The minimum weight you need to stay at 15ft of depth

And interestingly...because generally when discussing recreational diving it involves a single tank of gas...the amount of weight you need is going to ALWAYS be more at the end of the dive than the beginning of the dive because the only material variation in weight is the REDUCTION in weight from breathing the gas in that one tank. Which means we really only have ONE point to get started:

The minimum weight you need to stay at 15ft of depth


Why is too little bad?

Too little generally results in one of two bad situations (or both):