Marine software

I have an old Garmin shipboard gps that drives the autopilot just fine, has charts... I've since then replaced it with a Raymarine chartplotter. I also had a StreetPilot III that had NMEA output. I was able to synchronize the waypoints with both, and the SP3 was actually able to drive the autopilot, had NMEA output.

I've asked Garmin your question in the past. They said my nuvi would not output NMEA sentences. It only has 1 output (mini-usb) and they told me it doesn't output NMEA, just acts as a USB drive.

If you don't need to drive an autopilot, your 550 will still allow crude navigation. You can put it in off-road mode & it will navigate to 1 waypoint at a time, giving ETA... My nuvi 660 doesn't display nautical miles, I expect your 550 doesn't either.

And be careful because it's not waterproof.

If you need nautical charts, you would need to look at a product like BlueChart which can get very expensive.

Thanks for the information. Sounds like I may be better off buying a marine GPS. I'd like to be able to mark locations where there is good fishing and mark where I drop crab or shrimp pots.

My 550 doesnt have off-road as an option on it.

... if you buy one for your boat as well

I have a Nuvi 760 and thought I'd try blue charts on it with my boat just for the hell of it. All i need really is a visual of where I am for fog or simply just curious. My boats small enough I won't be out in rough weather.

I did not try routing with it, although the 760 supports it, but I found it worked just like I had it Topo mode. Showed where I was, direction, heading and displayed the marine information from the blue charts. I was using Bluechart Americas, and my test was done the great lakes (lake Ontario specifically). Worked fine I even put it on the suction mount on the dash. I decided to get fancy and put the upside down perl as my "car".

So if anybody wants to do it, it works fine for simply relaying waypoint and current position data. But no it won't interact with any navigational equipment other than your mind.

Since I wasn't about to buy another one for the boat - it was a fun experiment but for practical purposes, I imagine I would only use it for depth information, shipping routes/lanes and if visibility was poor or dark. That's about it.

Cheers.