OpenCPM to Garmin 610T

[BoatHunting]

Is it possible to communicate between OpenCPM and a Garmin 610T?

I'm running OpenCPM 4.6.1 on Windows 7.
The Garmin 610T is a handheld GPS.

The PC communicates with the Garmin but sees it as a storage device.

OpenCPM documentation indicates that the PC needs to see the Garmin as a serial port connected via USB. It doesn't.

[BoatHunting]

Systematic trail and error produced some success.

On Garmin 610T
Setup>System>Interface>Garmin Spanner {NMEA Sentences: On; AutoPilot Mode: Off; BAUD: 4800; Precision of Minutes: MM.MMMM}

On OpenCPM 4.6.1 running on windows 7
Tools>Options>Connection>Add Connection {Properties: Serial; Data Port: Garmin-USB; Baudrate:4800; Protocol: NMEA 0183; Priotiy 1; Control checksum: checked; all other options: unchecked}

On Windows 7 Device Manager
GARMIN Devices: Garmin USB GPS

What does this accomplish?
The position of the boat becomes visible in OpenCPM.