Free or low cost GPS navigation software?

[c_witch]

Originally Posted by thomasward00

I'm looking for the best freeware or low cost marine GPS navigation software, hopefully something that will show a depth chart, I will be purchasing a USB GPS Receiver.

Thanks in advance

My vote is for OpenCPN running under Linux. I happen to use Mint 12 currently. OpenCPN works very well ie version 3.0.x. Linux mint installs somewhat like Windoz but with way fewer questions from the wizard. It is also much more stable IMHO. I have NOAA charts for the us eastern seaboard and gulf as well as world wide charts CM-93 version II for the caribbean,cuban and canadian eastcoast waters. The canadian cm-93 charts were derived from the canadian paper charts. Even the paper charts can be wrong at times. Buy a dedicated depth sounder. I use a depth sounder/fishfinder combo as it also gives a nice display of the bottom contour as well. All the charts I mentioned can be had for free on the internet as well.

c_witch

[VK540]

Originally Posted by skygazer

One year later........... I had a strange experience last Saturday. I was sailing in Casco Bay (Maine, lots of rocks and ledge), running up close to two small rocky islands, and deciding whether to run between them (narrow, shallow) or around the outside of the outermost one (deeper, lots of sea room).

I looked at my Garmin and it showed my boat already outside the outer island, quite a distance from my actual position - it was a clear evening with plenty of light, sun just setting, full moon about to rise - good visibility. I checked several times, the Garmin - normally extremely accurate - was showing the completely wrong position for my boat. Since I was checking for depths, I could have gone very wrong if I wasn't relying on a paper chart and visuals, with the Garmin as a helper. When I rounded the outer island and tacked into it's lee and onto my anchor, the position was shown correctly.

So while the chart on the Garmin was accurate, my position as shown was totally inaccurate for a short while.

Glad it wasn't foggy!

Similar experience with my (less than one year old) Garmin one month ago. It taught me two things. Never rely on it alone and only sail into anchorages after dark that you already have a track for. Depth sounder showed 24 feet of water and my bow hit a rock which was about 30 feet long and 18 inches out of the water. My spot light wasn't working. My keel didn't touch bottom as there was lots of depth right up to the rock. The rock was not on the chart or not in the correct location, in fact after checking the area with the same gps on my buddies boat it this whole area is not accurate on the charts when it comes to depth and land locations. I paid over $3k for this particular unit. I have sailed into some tricky spots before and the plotter was very accurate but not this time and it cost me a haul out and some fibreglass repairs. I lost all faith that I had in my new unit. I was also sailing on a friends boat around the San Blas Islands in Panama last Feb. (his chartplotter was Raymarine, not sure what charts were loaded) and there was a whole Island that was not on the charts! We were night sailing and got lucky that time.

[skygazer]

Originally Posted by VK540

...Depth sounder showed 24 feet of water and my bow hit a rock ...My keel didn't touch bottom as there was lots of depth right up to the rock.

Bad event, sorry to hear it. When I hear depth sounders recommended I foresee the type of event you experienced. We have loads of rocks and ledge rising from deep water. A depth sounder would be great on a shelving bottom, but it's the rocks that scare me. I've almost hit uncharted rocks in Moosehead Lake, which is poorly charted.

Casco Bay just north of Portland is well charted, heavy ship traffic during the war, many areas wire dragged for rocks, etc. I had this year's Bluechart on the Garmin, so it was recent. The GPS had a clear view of a clear sky, and time to correct as I approached. Electronics are great to have, but not infallible.

I guess we need forward looking infra red radar, or forward looking sonar under the hull!

Two weeks ago I penciled in an uncharted rock in a narrow but beautiful and popular anchorage. It was off to the side, but I like to tack up to where I anchor and might need that space to get around other boats. I'd gone around in the dinghy at low tide and looked for hidden problems, as I hope to go back there sometime.

[delite]

Navionics has come out with apps for Ipad and android phones and tablets. Cost is about $50 depending on where you sail. Charts look pretty good
Mobile & PC App | Navionics

[GufShoz]

I use an app called "Charts" on both my ipad and iphone. It does everything I need.

[hellosailor]

"Two weeks ago I penciled in an uncharted rock in a narrow but beautiful and popular anchorage. "

All mariners are actually invited to send in that kind of information to DHA or G(S)IA or whatever the folks making the charts are calling themselves these days.

[skygazer]

Originally Posted by hellosailor

"Two weeks ago I penciled in an uncharted rock in a narrow but beautiful and popular anchorage. "

All mariners are actually invited to send in that kind of information to DHA or G(S)IA or whatever the folks making the charts are calling themselves these days.

I didn't know that, thank you.

I've been kicking myself ever since for not bringing a handheld GPS with me and getting the exact position of the rock. For most, it would not be a problem, too close to the cliff it fell from. Everyone motors up the center of the opening. I prefer to sail onto my anchor or mooring when possible. Due to light airs, contrary current, and an anchored 40 something foot catamaran that seemed 30 something feet wide, I ended up tacking back and forth right to the cliff to try to get through the boats already present. Each time I got to where I could make it, the same back and forth motor boat cut me off. I finally decided to motor in (hate that) but wanted to know just how far I could push the limits of tacking room.

[skygazer]

Originally Posted by milutin

speedy...ray marine etc....

I shortened the URL to disable it on my post. I got a strong warning from my McAfee anti malware not to go to the site, apparently some danger had been noted there. Could be a false positive, but I didn't go there and would certainly scan any download from a site that has a huge RED warning.

[denverd0n]

So what is that supposed to be a link to, anyway?

[skygazer]

Nice screen shot, looks good. Did you test the link you posted? Perhaps I got a false positive.