rtwo2008 wrote
I am not too familiar with GPS and how it works.
Satellite triangulation.
rtwo2008 wrote
1- Any units available for under 100$?
Maybe. Note that marine units typically cost more, they must be resistant to saltwater, splash-resistant, etc.
rtwo2008 wrote
2- Does the unit need the map of Lebanon? If yes, is it easy to install it?
What would a map be useful for if you only want to save the location of a spot in the sea?
PS: I think my iPhone can do that... save a spot using GPS. Most Android smartphones too, I guess.