Introduction

Marport Trawl Positioning System indicates the position of the trawl gear. Trawl doors are displayed on the screen to help you maneuver the gear with more ease and security.

The position of the trawl gear can be calculated with two different types of sensors:

With Spread sensors, it is calculated using depth and bearing data received from the sensors and using the length of warps. Warp lengths can be obtained from winch control systems giving accurate wire measurements.
With Slant Range sensors (also called pingers), it is calculated using the distance from the sensors to the hydrophones, depth and bearing data received from the sensors.

Each option has its advantages: Spread sensors offer a more rapid update, a longer battery life, a longer range and can be used alone. This is the preferred option. Slant Range sensors are usually used in addition to Spread sensors, so you need two pockets on the doors. They are more suited to fishing vessels that do not have winch control systems.

Spread and Slant Range sensors also exist in smaller size to meet the needs of smaller trawlers: a Mini Spread Sensor (stubby bottle) with a standard or slim housing and a mini Slant Range (small bottle).

You can use Marport Trawl Positioning System to display the trawl position on Olex, MaxSea version 12.