While I understand the logic of your idea, FORGET IT! While a decent marine chartplotter
may seem like a 'jumped up TomTom', you're forgetting all the extra info that is included.
Sure, for coastal cruising, your car/phone GPS
will give you a decent idea of your position in relation to the coast and certainly will give you an acurate Lat/Long fix, however, it WON'T give you any idea of your imediate surroundings. ie, small rocks, even proper islands (just no need to show them on a land based GPS), depth
, sunken wreaks, marker bouys, even marinas
, etc, etc, the list goes on. Theres also all the extra stuff than can be interfaced with a decent setup, radar
, depth sounder
The only reason to use one on a boat would be to backup the existing marine
chartplotter to give you a Lat/Long fix in conjunction with proper paper charts
Now, if you mean using it in conjunction with some sort of software
upgrade that would give you acurate marine charts
on the original unit, then they may be something in it. However, this is one item that i'd much rather spend the money
on to get it working PROPERLY in the first place. Saving even a couple of thousand, only to run aground or hit a rock at night seems like a false ecconomy to me.