Model 106D Lighted Drifting Buoy

Model 106D configured as a surface drifter
(click on image to enlarge)

Model 106D configured as a current-cross deep drifter
(click on image to enlarge)

Overview

The Model 106D is a Lagrangian (drifting) buoy that is located visually using a retroreflective witness staff and a solid state light. It is intended to be monitored and tracked by personnel in small boats using handheld GPS, and is recommended for use when budgets are minimal or for areas where the risk of pilferage or shipstrike is high. Lagrangian flow data provided by the Model 106D is useful in current measurement, larval fish studies, oil spill or floating debris tracking, discharge dispersement calculations, and similar work.

Physical

The default configuration of the Model 106D is a standard Davis/CODE surface drifter designed to track the top 1 meter of surface currents. The drifter can be field converted to use a deep cross drogue (1 meter wide x 2 meters deep) that provides a drag ratio of approximately 15:1 when tethered at 3 meters. Other drogue types are available.                 

Electronics

Light is generated by a side emitting high output LED emitter and further directed into a 360-degree horizontal band by a focussing lens. Although not certified as an aid to navigation, the light meets the USCG intensity standard for 2-mile visibility.

Excitation voltage to the LED is provided by a high efficiency switching regulator controlled by a PIC microprocessor. Use of the processor allows unique flash patterns to be programmed into each light. The light can be shut down by an external magnet (supplied) without opening the case. The battery pack provides over 1000 hours of continuous operation.

The light color and rhythm confirm to “special marks” as defined by the maritime buoyage system of the International Association of Lighthouse Authorities. Color is amber, rhythm can be anything other than rhythms associated with white lights that are described in sections 3 (cardinal marks), 4 (isolated danger marks), and 5 (safe water marks).

Default rhythms for the lights are single Morse code letters EXCEPT for the following:
1) Morse "A" (used for Safe Water Mark)
2) Morse "E" and "T" (potential confusion with Safe Water Mark).
3) Morse "I" and ""M" (potential confusion with Isolated Danger Mark).
4) Morse "S" and "O" (potential confusion with East Cardinal Mark).

Specifications