Marine GPS can be very expensive, the cheapest GPS will set you back over $500 and that is before taxes buying chart/maps and installation. A cheap alternative to spending that money is simply using a cheap tablet and paying around $9.99 for the Navionics App or if you want the more Hi-Def pay $50.
A tablet is very convenient because it is a touch screen and is quicker to input information, also you will be able to set way-points as well see your depth and speed at which your are traveling. Depending on your memory you will also be able to add more charts as needed.
Just remember to make sure that you have a battery charging station to keep your tablet charged as well as a very sturdy mount for your tablet to keep it from shaking as well as water proof and glare proof cases and you will be fine. Remember this is just and alternative if you can’t afford to buy a Marine GPS however it is wise to always have a backup GPS.
Tight Lines and fish on..