BriarTek ORCADSC User Guide

Overboard Recovery

Communications Apparatus

(ORCA

)

ORCA DSC User’s Guide

®

BriarTek, Inc. Technical Support: [phone], Email: [e-mail]

©2009 BriarTek Incorporated

, URL: www.briartek.com

2

Introduction

ORCA® is a personal saltwater or manual-activated man overboard (MOB) alarm system
developed by BriarTek Inc. The system is utilized by the U.S. Navy and other mariners to aid in
the rescue of an MOB victim and includes a transmitter, receiver, and direction finder. The
ORCA® DSC transmitter alerts a MOB event on VHF marine channel 70 and 121.5 MHz. When
the transmitter is activated, it transmits a digital selective calling (DSC) distress message on VHF
marine channel 70 from the victim to any vessel operating with a DSC complaint VHF marine
radio. ORCA® DSC also transmits a distress message to an ORCA® receiver on 121.5 MHz
during a MOB event. The receiver emits an audible alarm and displays the ship type/hull number
and serial number of the transmitter on the ORCA® receiver’s LCD. The transmitter also emits a
signal that is received by the direction finder and other standard search and rescue (SAR)
equipment to locate the MOB.

ORCA® DSC Parts Overview (See figure 1)

A - Antenna
B - Manual activation/ deactivation recess
C - Water sensors
D - Distress marker light (DML)
E – Battery door

Modes

The ORCA® DSC has three modes:
♦ ARMED - Each transmitter is ARMED after

a 3 volt CR123 lithium battery is correctly
installed.

♦ TRANSMIT - The transmitter goes from

ARMED to TRANSMIT mode when it is
automatically activated by submerging it in
saltwater for a minimum of 3 seconds or
when it is manually activated. After the
transmitter is activated, it emits a DSC
message on VHF marine channel 70 per the ITU-R M.493-11 protocol to its registered
VHF marine radio. It repeats this message every five minutes for 30 minutes. If the unit
has not been turned off after 30 minutes, it will then transmit a group distress message to
DSC equipped radios within range of the transmitter. The unit also transmits a FM distress
signal at 121.5MHZ after the initial DSC transmission. This sends the transmitter

®

identification to the ORCA

receiver. After sending this FM distress message for
approximately 1 minute, the transmitter switches to a non-data transmission for 40
seconds. This allows the DF to track the transmitter more effectively. After every 40
second non-data transmission, the unit transmits identification information to the ORCA®
receiver for 9-15 seconds.

♦ DISABLED - The transmitter is DISABLED when the battery is removed or the battery

runs out.

Figure: 1

3