Summary: I've decided to purchase this item due to my urgent need of a back-up GPS while fishing offshore. You just can't have enough back-up when it comes to safety. I like this product because of it's size and portability, also for it's internal antenna configuration; not having the need to mount an external antenna and dealing with wires/cables. Additionally, its capability to operate using alkaline batteries is also a plus (+).
Summary: This is a great portable chartplotter for use on my sailboats. It can be carried from boat to boat, for use in the cockpit or down below or on deck. I like the fact that it can either be hardwired or powered by AA batteries. No need to recharge--just replace the batteries. One set of 4 batteries lasts almost 24 hours with continuous use, and a meter tells you how much battery power is left.
Summary: I have a 176c mounted in one of my trucks and the family finds it easy to use and simple to navigate that I purchased a second unit for them to have when I am using mine. An optional antenna helps with reception in remote areas. The battery life is decent considering the size of the unit although vehicle power supply makes for flawless operation.
Summary: The 176 screen is hard to see in the sunlight and the size of the print, such as street names, is too small. I have not used the unit on the water yet becuase I need to purchase data card for the Southeast coast. Not cheap either! The 276C is a far superior unit with better a screen and graphics so save your money if you can for that unit. I will probably but this unit on sale soon.
Summary: The Ebay price range ($200-$300) for this model makes it number one in it's price class hands down! I've been using mine for fishing/boating and it works great. It has all the features you could want in a GPS Chartplotter but can also be used just as well in you car. You can go wrong with this unit.