On compliance in coastal moorings

To better understand mooring behavior in the coastal ocean, the WHOI cable modeling program was used to examine several chain catenary and compliant elastic tether mooring configurations. The chain catenary is used most often, and is the most robust, although if many instruments are used in the mooring line and a depressor weight used to keep the mooring more vertical in high currents, the tensions in the mooring can easily exceed 15,000 lbs in heavy seas and currents. On the other hand, elastic tethers on moorings with few heavy instruments in the mooring line, can provide a lighter mooring with smaller, lower cost buoy and hardware that can still survive the severe conditions in the ocean environment. Tensions in these moorings rarely exceed 2,000 lbs. The high tensions in the chain catenary moorings are due to the heavy instrumentation that must be accelerated by the buoy as it follows the waves, and is generally too large for compliant elastic tether configurations