In an underwater acoustic bearing sensor, the vector sensor, heading sensor, and pitch and roll sensor are held in a common mounting ring to ensure that their coordinate systems are collinear. Recoverable Strains are as large as 9 percent, and in special circumstances as large as 22 percent. The BBU processing pool is configured to share the processing load of several sectors. A method for use in transferring semisolid material from the container is also disclosed. The closing operation of the duct cap is delayed by using a frictional force developed between the joint member and the frictional member. The invention involves a sequence of exchanges between an aiding source and a receiver that serve to provide aiding information to the receiver so that the receiver’s location may be determined in the presence of weak satellite transmissions.