Navionics on Android route finding facility

[RichardS]

I don't this will be news to everyone but I was helping a fellow sailor deliver his cat from our marina to another marina in Croatia with a large enough travel lift to take his Lagoon 450. I took my Android tablet along as a backup and was pleased I did because there is some kind of issue with the new-fangled touch-screen chartplotter on his boat and when I fired up my tablet and touched our destination it asked me whether I wanted a route to follow. It has never asked this before so i said yes and, like a car satnav, it plotted a tortuous but perfect route out of my marina, around the islands, and right into the destination marina.

It then tells me total distance and time, distance and time run and distance to go and ETA and these are constantly updated as the journey progresses.

I believe that Apple users have had this for some time but now we Android users have it as well .... and it's very clever so give it a go.

Richard

 

[Moonbeam]

I've just started playing with Navionics on an Android tablet as a back up to the fixed Garmin Chartplotter. Pretty happy with it and I tried the auto route function from our half drying mooring in the furthest reaches of Plymouth Harbour down to beyond the breakwater and to my astonishment, it actually plotted a reasonable course. It did cut a few corners quite fine and I would not want to rely on it, but as you say, not a bad toy and handy if you are in a real fix. But I do worry about the accuracy of the navionics charts at times (although it might me my android tablet GPS accuracy at fault) but if you see the track below, it has us going outside the port buoy going through the narrow 'bridge' channel. We did not, the Garmin cartography as has always been spot on everywhere we have been along the south coast, and it's track shows us inside the port buoy. As I say, it may be the tablet fix is less accurate than the chartplotter and nothing to do with the Navioics cartography.

 

[[3889]]

I've had mixed results with autorouting, sometimes giving an ideal route and sometimes crossing land. I doubt the GPS will be less accurate on a mobile device. I use Navionics on my phone as my primary navigation device and have always found high levels of accuracy e.g. showing which pontoon I'm on or passing under bridges. One important setting for autorouting is boat draft. IIRC it is 10m by default but make sure it's not less than actual draft.

 

[RichardS]

I've just started playing with Navionics on an Android tablet as a back up to the fixed Garmin Chartplotter. Pretty happy with it and I tried the auto route function from our half drying mooring in the furthest reaches of Plymouth Harbour down to beyond the breakwater and to my astonishment, it actually plotted a reasonable course. It did cut a few corners quite fine and I would not want to rely on it, but as you say, not a bad toy and handy if you are in a real fix. But I do worry about the accuracy of the navionics charts at times (although it might me my android tablet GPS accuracy at fault) but if you see the track below, it has us going outside the port buoy going through the narrow 'bridge' channel. We did not, the Garmin cartography as has always been spot on everywhere we have been along the south coast, and it's track shows us inside the port buoy. As I say, it may be the tablet fix is less accurate than the chartplotter and nothing to do with the Navioics cartography.

That's interesting. I've also noticed that the Navionics on the tablet is slightly less accurate that the Raymarine chartplotter but as both are using Navionics cartography I think that it must be the GPS chip in the tablet which is not quite as accurate. However, the difference is not noticeable unless I zoom right in so, for example, the fixed chartplotter shows my boat next to it's proper finger if I zoom in on the marina whereas the tablet shows us parked alongside the adjacent finger ... so it's probably only a difference of 5metres at most.

Whether the course finder cuts any corners is presumably controlled by what you set your draft and sender depth to. I guess that if you build in a slighter greater safety margin the Navionics will respond in kind.

One quirky thing compared to a car satnav is that, if you want to bother, the fuel consumption is set in litres per hour so when you first plot in the course before you are moving it calculates the distance as say 20Nm and, as you are moving at 0.1 knot bobbing on the mooring, it calculates the journey time as 100 hours, or whatever, and tells you that you will use 500 litres of fuel. At first I thought I have done something wrong but, of course, once you get moving it sorts itself out.

Car satnavs would use mpg of course, so this error wouldn't arise but it's not a big deal.

Funnily enough the ETA seems to stay blank until the boat starts moving so I'm not sure why Navionics didn't use a similar logic for the fuel consumption.

Richard

 

[Moonbeam]

That's interesting. I've also noticed that the Navionics on the tablet is slightly less accurate that the Raymarine chartplotter but as both are using Navionics cartography I think that it must be the GPS chip in the tablet which is not quite as accurate. However, the difference is not noticeable unless I zoom right in so, for example, the fixed chartplotter shows my boat next to it's proper finger if I zoom in on the marina whereas the tablet shows us parked alongside the adjacent finger ... so it's probably only a difference of 5metres at most.

Whether the course finder cuts any corners is presumably controlled by what you set your draft and sender depth to. I guess that if you build in a slighter greater safety margin the Navionics will respond in kind.

One quirky thing compared to a car satnav is that, if you want to bother, the fuel consumption is set in litres per hour so when you first plot in the course before you are moving it calculates the distance as say 20Nm and, as you are moving at 0.1 knot bobbing on the mooring, it calculates the journey time as 100 hours, or whatever, and tells you that you will use 500 litres of fuel. At first I thought I have done something wrong but, of course, once you get moving it sorts itself out.

Car satnavs would use mpg of course, so this error wouldn't arise but it's not a big deal.

Funnily enough the ETA seems to stay blank until the boat starts moving so I'm not sure why Navionics didn't use a similar logic for the fuel consumption.

Richard

Thats all useful to know. :encouragement: