Turn the unit on using the small power button. Then use the larger button to toggle to the following settings.

SETTINGS
LANGUAGE         ENGLISH
TIME ZONE        GMT (unless away at Comp)
UNIT            NM (for knots)
TIME FORMAT      24H
DATE FORMAT      DD/MM/YY
ARRIVED - NA
MAP DATUM        WGS84
POSITION         DD°MM'SS.S"
USER GRID - NA
POWER MODE       NORMAL
DGPS SOURCE      OFF
INTERFACE        NMEA(38400)
BACKLIGHT        ON
BACKLIGHT TIME   10 SECONDS
CONTRAST  As you like
EXT.POWER MODE   OFF
USERNAME         sailnumber name (example: Z DAVIS 47)

SPEED AVG TIME   10 SEC
SPEEDGENIE       25 KTS
HOLD KEY         KEY LOCK
SERIAL NO.
VERSION          V1.3(B1123T is the latest) (from http://mtbest.net/setting-up-navi-GT31.htm)
COLD START only used when used for 1st time or new location

MEMORY CARD
LOG SWITCH       ON-FIX
MIN SPEED        5 KTS
NMEA ITEMS       SBN 1SEC
FILE SIZE        CARD SIZE
FORMAT CARD      FAT16 (do once with a new SD-card)
REMOVE CARD NA

DATA LOGGER
INTERVAL         1SEC
MIN SPEED        5 KTS
SAVE TO CARD NA
CLEAR NA

Once this is all set go to Speed (Checkered Flag Symbol) then toggle to the revolving speeds. Hold the big button in squarely for 3 second and that locks the buttons. I recommend putting it into an Aquapack for security and extra water proofing and then go out on the water and get some fast times.

Once you have finished your session for the day turn off the unit by unlocking the buttons (3 Seconds large button) and then hold the small button down until it switches off.

Down loading the software on to GPS Results

Download the latest software from www.gps-speed.com (free for 30 days then its 29 Euros to buy) and follow the instructions. Take the memory card out of the GT31 and put it into a card reader attached to your computer ( most Laptops have them now days) and open the file on the card and then you can see the tracks you have made analysis the speeds over multiple distance times etc. if you have registered with GPS speedsurfing and put in you favorite spots equipment used etc. You can put in your username and password into the program and it will up load your session automatically to your sessions on GPS speedsurfing site.

Sounds a lot but once its done you can upload and look at your sessions in seconds.

HONEST!

the best thing then is you can then compare your results with your mates, local club, nationally and even internationally.