Sat2Chart

[Slovak]

Originally Posted by Jon Hacking

That's fabulous, Slovak! Let me know when you're ready & I'll link to you from our Chart Downloads page. Or are you ready now?

Presumably you're going to be using CMap

Ready now, I'll add more Med countries as my time allows.

I'm curious about the desire for downloading Navionics, CMAP, etc.

For me, the most substantial value of Sat2Chart is to download satellite imagery - because that's the only way to access those offline. I've got charts in the chart plotter. I can buy Navionics. I can pay the nominal fee for o-charts for OpenCPN and keep using them after the 1-year expiration.

What's the improved use case scenario of using downloaded Navionics and CMAP charts vs those same ones available through built-in means?

[Jon Hacking]

Yeah, all good questions, Slovak. I guess it's mainly having everything in the same place, rather than having to look on different devices. While nautical charts have significant errors & omissions, they do have depths, which the satellite imagery lacks. Both Navionics & CMap are better with depths than CM93 (which is all many folks have), & the versions downloaded with SAS are probably the latest & greatest. Yes, a practiced eye can often tell depths from the color of the water in satellite imagery, but there are lots of times that's not really good enough. And when planning a route along a coastline, it's nice to be able to see everything in just one place.

[Slovak]

Originally Posted by Jon Hacking

I guess it's mainly having everything in the same place, rather than having to look on different devices. While nautical charts have significant errors & omissions, they do have depths, which the satellite imagery lacks.

It's a good thing to have options, and different people route plan and navigate differently. In my case I actually prefer to be looking at different charts - when we sailed to Alaska last year, we consulted 3 different sources AND satellite imagery as well. So to me the "benefit" of having everything in the same place could actually be a limitation. But I understand your point.

Originally Posted by Jon Hacking

Both Navionics & CMap are better with depths than CM93 (which is all many folks have)

Considering that most available CM93 charts are from 2015, that seems a bit scary. Especially with the number of available sources of updated electronic chart resources that can be had for a nominal fee, relative to other cruising expenses.

[sv_pelagia]

CM93 that work in OpenCPN are older than 2015.

2012 or earlier.

[Slovak]

Originally Posted by sv_pelagia

CM93 that work in OpenCPN are older than 2015.

2012 or earlier.

The downloaded version I have (don't recall the source) and have used in OpenCPN is labeled cm93_2015 - so I assumed that indicated the year of those charts.

Personally, I only use the CM93 charts for general planning and daydreaming. It's nice to have the world charts in under 2G of space, and the ability to open up a location when reading someone's blog in a place that I'm not familiar with.

For detailed planning purposes in OpenCPN, I have used NOAA and o-charts.

[Jon Hacking]

Many folks have copies of CM93 that say they're created in various years, but I believe CMap stopped producing CM93v2 in October 2011. Terry Sargent (of Valhalla fame) has one dated 2015, but it's really a much older version.

The problem was that they were being handed around too much, so CMap went to CM93v3, & encrypted them. I've seen cracks for these if you wanted to use old versions of MaxSea (up to about v12) but by then OpenCPN had progressed enough that most cruisers (that I knew) moved to OpenCPN instead.

The best version of CM93 I've seen was a compilation of all older versions, which gives the latest versions of the charts as well as any older chartlets that had been deleted over the years (like the entrance to Solomon Atoll in Chagos).