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Graham W:
Bob Bradfield, who produces the marvellous Antares chartlets on Memory Map (at approximately 10x the scale of UKHO charts), writes as follows:
“It may interest you to know that I have started on a new series of charts specifically for shoal draught boats, drawing c. 0.5m or less. Hitherto I have tended to stop at chart datum but realise that for much of the lunar cycle there are large areas of water suitable for the anchoring of such boats, often offering more shelter than is available to deeper draught boats.”
Here’s a link to the Antares website http://www.antarescharts.co.uk/.
I can’t wait to see the new series!
Graham W:
Here for comparison purposes are screen shots of four different chart apps covering roughly the same area of the Medway Estuary.
The first is Navionics, which as you can probably see has plenty of clear detail and lots of functionality, curse them. Second is C-MAP, which isn’t bad and has the same colour scheme but perhaps less detail than the third, an HMSO raster map on Memory-Map. Lastly Savvy Navvy, pretty to look at and handy for planning in advance using their wind and tidal atlas algorithms. Not so easy to follow in real time when waves and the weather are causing distractions.
Graham W:
Here are the same four apps zoomed in to show more detail. In the same order as before - Navionics, C-MAP, HMSO raster and Savvy Navvy.
Navionics has its additional sonar imagery switched on as an option and shows quite a bit more detail than the next two. C-MAP seems to zoom in more clearly than the HMSO raster, which has gone a bit fuzzy around the edges. I’ve noticed that Savvy Navvy takes much longer to fire up on my ancient iPad than the other three, presumably because of the complicated wind and tide algorithms that it has to load.
Graham W:
The first attachment on this one is another view from Navionics, showing a different way of looking at relief shading (one of several). Navionics looks to be the only app that shows tidal channels running off the mud flats. How accurate or useful these are is anyone’s guess.
The second chart is from one of my favourite Memory-Map packages, Antares charts of the West Coast of Scotland. Although it looks like an HMSO chart, these charts are produced privately and at about ten times the scale. This particular chart is of part of a secret anchorage amongst small islands off the NE coast of Barra in the Outer Hebrides.
Graham W:
If you’re considering swapping over from the Apple ecosystem to Android, or vice versa, there is a potentially significant hidden cost. Expenditure on apps in one system may count for little in the other, so you may have to buy them all over again. More technology bunkers and oligopolistic practices.
If you can get your timing right (and it may be a big if), it might not be quite so bad with navigation apps like Navionics that charge an annual subscription. And perhaps others that make money from in-app purchases may also present a loophole if you can somehow link back to the purchases in your existing account. In particular Memory-Map, recently upgraded to Memory-Map for All, seems to be cross-platform and able to link to previous add-on purchases (such as Antares and UKHO charts) whatever platform you are on. You may have to jump through a few hoops to achieve this but it should be worth it. Bless!
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