Instrument recovery from the deep ocean

A gas generating (latent) buoyancy system or a fixed system comprised of solid buoyant elements can be employed in the recovery of instrument packages from great depths. The difference in characteristics of the two classes of recovery devices is discussed. The latent system offers better performance and fewer handling problems but at a higher purchase cost. It is consequently favored for emergency buoyancy and other special uses, whereas the fixed buoyancy system is employed more in conventional practice.