How do I program my lowrance to locate reefs if I have the lat log reference?

you only use if you connect a radio with long/ lat display or auto pilot. otherwise do not connect them

Point your web browser at http://www.facebook.com

If another account comes up, log out of it by clicking the down-pointing triangle in the upper-right then clicking "Log Out."

If you then still can't log in to your account, click the "Forgot your password?" link located just below the password box on the login page.

The NAVMAN trackers are no longer available as the company stopped making marine products. You can however find current products at www.lowrance.com.
The closest you can find is a Lowrance Elite 5mHD
http://www.chsmith.com.au/Products/Lowrance-Elite-5m-HD-Chartplotter.html

In case you want to refer to a manual for 5505/06 refer this site.

http://www.navmanmarine.net/upload/Marine/Internet_Manuals/Tracker5505_5605/English_T5505_5605_manual.pdf

You can still find some old 5505 units at speciality marine online stores. Give this a try.
Northstar Navman TRACKER 5505

yes go to new way points put in lon and lat.click enter

Here is the way to find the Lat/Lon Info on TomTom.
Tap on main screen. You will be taken to Main menu 1 of 2. Tap on the arrow. You will move to Main menu 2 of 2. Tap on Browse map. You will see the lat/Lon info on the bottom left hand corner (of a selected location) Tap on another location and you will see that the lat/Lon will change to that of the newly selected location. You can use the slider on the right hand side to zoom in or zoom out so that you can get the Lat/Lon info of far off locations. However, for this purpose, google maps would be a better option. But if you know the address, use the find button which will give you easier access to Lat/Lon info.

Yes, if you download the newest firmware upgrade version 1.2 it will add in other projections and datums, as well as fix other known issues. I would recommend that you run both the 1.1 and 1.2 upgrade for your Sierra, the 1.1 upgrade will fix some issues with the base map.

Both upgrades can be found at the following location: http://www.lowrance.com/en/Endura/More/

I hope this helps.

manuals can be downloaded at http://www.lowrance.com/en/Downloads/Manuals/

You can probably get the parts from a dealer, or any marine electronics retail like Bass Pro and Cabelas or any of those kinds of places.
You can buy accessories from Lowrance at www.lei-extras.com

Not sure about the speed transponder? but if you are referring to the transducer, you probably need to go to this link

http://www.lei-extras.com/store/search.asp?SearchType=Category&Category=200+khz+transducer

That first item, part number 106-72, is most likely what you are referring to.

I eventually solved the problem by firstly doing a restoration of default settings. This allowed me to toggle but it was between two different presentation styles of latitude and longitude. To restore the grid co-ordinates option I went to main menu, the Setup, then then toggled to location and re-selected UTM UPS as the location format.

Create and save a waypoint for any location then update that waypoint with the lat/long you were given (just click on the lat/long and key in the new coordinates).

I've had great success locating full user manuals for the Lowrance products at:
http://primus.lowrance.com/support/resultDisplay.do?gotoLink=6&docType=1000&contextId=857%3A6.21%2C1808.1840%2C6.21&clusterName=ClusterPublic&lang=english&docset=%2FDocuments%2FUnits%2FLowrance%2FGPS&contentId=32918bdd-e14e-42de-8bf0-81e9cb11ab7e&responseId=135ccbe2cfd4f608%3Adcb03b%3A11a44cb2b51%3A5f29&groupId=4&answerGroup=1&score=480&page=http%3A%2F%2Fprimus.lowrance.com%2Ficr%2Funits%2FLowrance%2FGPS%2FGM4800Mpub.htm&result=1&excerpt=GlobalMap+4800M&question=lowrance+4800&resultType=5000#Goto6

If that URL doesn't work, please visit Lowrance.com, and select self-service support.  Click the "Product Information" link on the left side of the screen then enter your product name in the supplied field.  You should be able to find any information on the GPS you have!