Abstract: A method for determining the cumulative lateral slip of a towboat or combination barge tow/towboat. The method comprises providing two positional sensor instruments mounted at either end of a combination barge tow, each positional sensor capable of determining its geographical location from radio transmissions from, e.g., GPS satellites. The velocities of each positional sensor, both parallel and lateral (perpendicular) to the bearing of the barge tow, are determined. The cumulative sum of the absolute differences of the lateral velocities of the two positional sensors over time is calculated, stored and displayed by a microcomputer.

Abstract: A method for assisting tug boats, work boats and other vessels to navigate no-passing zones, such as narrow channel areas, along an inland and other waterways to avoid passing or overtaking other vessels having the right-of-way according to established waterway rules of the road within the no-passing zones. The method is implemented within an executing computer program, using a database of mile mark distances and of no-passing zones along the length of the waterway.

Abstract: A method for determining the cumulative lateral slip of a towboat or combination barge tow/towboat. The method comprises providing two positional sensor instruments mounted at either end of a combination barge tow, each positional sensor capable of determining its geographical location from radio transmissions from, e.g., GPS satellites. The velocities of each positional sensor, both parallel and lateral (perpendicular) to the bearing of the barge tow, are determined. The cumulative sum of the absolute differences of the lateral velocities of the two positional sensors over time is calculated, stored and displayed by a microcomputer.

Abstract: A carrying case for a portable two-way radio and designed to be attached to various points or straps on a Type V floatation vest used as a work vest by crew members on tug boats, tow boats and other inland or intra-coastal waterway vessels. The carrying case is comprised of a receptacle and strap. The receptacle is formed of a flexible material and has an open top and front, rear, bottom and two side surfaces. The strap is mounted longitudinally to the rear surface, and passes through a D-ring attached to the top edge of the front surface. The strap has fastening means on either end for securing the two ends together. The case is then attached to a work vest by passing the strap through an attachment point on the work vest above the case, then through another attachment point below the case. The ends of the strap are then tightened by the fastener means.