I have a Garmin 172C gps in my boat. This product is discontinued by garmin, but still for sale in several stores and sites. The 172 has a slot on it that accepts a chip that has detailed information of specific areas.

Does anyone know the name or model info on the chip that I need to buy? I am in Louisiana, but plan to boat in Florida/Alabama also. Will I need two chips, or is there a chip that covers the Gulf from Destin to Texas?

Mac, west marine or boaters world have them.I believe cmap is the company.The website has demarcation lines that show you coverage of your intended area of boating.they cover a huge area for roughly 150 bucks each.They burn them in the store while you wait.

Go to Garmin's web site and look it up. They have great support for all their products.

I had the 172C in my old boat. You can buy the chips at West Marine. They are called Blue Chart chips. The Garmin website will give you the info on what areas each one covers. I had one chip that covered the Gulf area around Texas and LA, and had to buy a separate chip for Florida. That is the main problem with this unit, you have to buy a separate chip for different locations.

eBay is probably the place... a ton of used chips floating around out there now.

I have an old Chesapeake Bay Navionics Navchart chip that I don't use anymore. I will have to check the part # on it to find out what it fits.

1chip Brownsville-Morgan City
1chip Morgam City to just north of St. Pete
another chip south to Key West and up east side of state.
Middle chip above may include the northeast part of Fla. for Jax area.
About a buck sixty a chip.
The Garmin 190 something model (196?) has all the chips built-in for , I believe, the Western Hemisphere or at least the U.S.

The Navionics chip I have is numbered US634XL from 4/02 @ 128Mb for the Chesapeake Bay and surrounding tributaries.

If you have a laptop computer you can just buy a blank chip and upload any number of charts up to that maximum memory capacity. With the maptech software you can do everything at home on the pc; plot routes, waypoints...ect and upload it by plugging into the USB port.
I have a 182C & a 3210 with the entire east coast on them.

Here's one that I used to get a new chart for my Standard Horizon unit and they have them of most other manufacturer's:

http://www.landfallnavigation.com/bluechart.html

Just type in your model and it will pull up a page with the charts for it.