So I'm trying to make do with my dad's old Humminbird Matrix 25 with GPS until I can afford s new unit. He had a TON of waypoints stored but I can't cipher thru them all an figure out what they belong to. They weren't grouped or named anything to be able to figure it out in a time efficient manner. I can't seem to find .gpx files of lakes downloadable anywhere on the net. Can anyone point me in the right direction so I can get a few lakes on my computer or is this even a feasible path I'm trying to take?

I'm not familiar with HB's Matrix units.

Exactly where are your dad's waypoints stored?

But if you have a .GPX file saved of them, then download HumminbirdPC from HB's Support website. If HBPC can open this GPX file, then HBPC has a function to display the data with Google Earth. And you can determine waypoint locations.

Another option is if you have a friend with a Lowrance HDS Touch unit. If the Touch can open the GPX file, then you can view and even use the Touch's Region Export function to separate the waypoints by lake or region.

The MATRIX units use the same Export format that the current core units do. The data is in a Matrix folder when exported from and imported to the unit.

Ok, probably should have expounded a little more, I've been able to download the data FROM the Matrix unit but still, I'm having to sort thru them one by one, using Google Maps to pinpoint and try to rename them to something recognizable. I'm trying to see if I can more or less start over. He didn't have any custom points saved so I'm not losing any secret fishing holes or anything.

Waypoints are created with the unit by pushing the MARK button. You can do that anytime you want.

You can do that on the water when at the location you want to save.
You can do that in Simulator while viewing the map and putting the position curser where you want a waypoint and then pushing the MARK button.

You can save what you have on a memory card or on your computer and/or with HumminbirdPC and delete all on the unit and start over.

What you exported is still on the unit and will be until you delete that data from the unit's memory. All you did was copy the data that was in the unit's memory. The unit does not use the data from the memory card and it is never on a card until it is intentionally Exported to a memory card.