So I got my first navionics enable sonar/finder a year ago, now getting message that I'm expiring. Why would I want to renew. Do you guys renew every year, what happens if I don't.. They say renew at half price, I have navionics+... $149.00 for the renew,,, half price?? whats up?

You get a year of Freshest Data Updates with a new purchase of any Navionics map card.

If you want to continue having the capability of updating to the current maps, you have to maintain the Freshest Date subscription. If not, don't do anything, your data won't self destruct.

Navionics stopped putting out annual editions after the 2009 issue and started the Freshest Data program in mid 2010 so you can have new and current maps as they were available.

As a matter of fact, little really changes on most lakes. The most data changes are in salt water areas such as spoil and dredging.

I find little to no benefit to update if you are fishing freshwater.

Re-surveys change the maps and their details a lot. Lake Fork and Kentucky Lake are a couple of examples I am familiar with.

Not only that, Sonar Charts can change daily for a particular body of water if you or anyone else is providing data for that program. I do.

Right now with the Sonar Charts program, Navionics is averaging around 20,000 updates per week for all of the US and Canada. No, it will not always be on your lake but in most cases each major lake has several updates per month. Perfect example is everytime I launch on Rayburn or Toledo Bend, I record data and upload via the Sonar Chart program. If you go to the Webapp, and toggle the button in the bottom left corner, that will turn all of those updates on and off and you can see the amount the body of water you fish has changed over the past few years just since the program started. I know on Toledo Bend there are entire flats that will lose all contours once you turn the layer off, but with it on the entire flat is in 1' contours.