A little more information on the Triton systems:
Triton's sawfish: An operator works in a control booth on a barge, directing the submarine the size of a car or truck to the base of a standing tree. Cables and air hoses connect the sub to the control booth above. A hydraulically powered grapple grabs the tree, and the sub screws a large air bladder to the trunk and inflates it. After the Sawfish saws the trunk with its 40-horsepower electric chain saw, the air bladder lifts the tree to the surface where workers then remove the bladder and the tree’s limbs. In three hours, the Sawfish can cut 37 trees. However, Triton does not publish how much time is required to capture the logs, remove the air bags, and trim the branches before any timber can be transported to mills.
Triton's SHARC™ Harvester is described as a versatile underwater logging system capable of harvesting trees in shallower reservoirs (less than 40 meters) where production and maneuverability are critical. Trees are located using sonar and video, the telescopic arm extends the cutting head to the base of the tree, where the grapple attaches to the tree and the saw cuts as close to the base of the tree as possible. The tree stem is then raised to the surface and into a floating bunk storage system. Triton describes the SHARC as basically an excavator attached with a telescopic arm and grapple-cutting head. This would indicate only basic up and down motion, and any maneuvering must be done by barge positioning.
This write-up comes directly from Tritons website, and seems to indicate that their SHARC now utilizes a grapple system that eliminates the need to attach air bags to trees when harvesting in shallow water.
