Here comes the 21st century

I wanna dance with Harry Dean

Drive through Texas in a black limousine.

I want a piece of heaven before I die.

I wanna a pair of high heels that catch the lights up on the Ferris wheel, but what I really want I just can't buy.

Here comes the twenty-first century. It's gonna be much better for a girl like me.

- Debbie Harry: I Want That Man

Despite Ben Pester's protestations in his book “Through the Land of Fire” that Marelle was better without too much modern technology, we couldn't resist upgrading her instruments to a full set of Tack Tick, and I got a bit carried away and added a Digital Yacht iAIS to link everything up to my iPad.

To be fair she did already have a Furuno GPS and Icom VHF on board, which we have kept, along with a broken Navtex, and a Seafarer depth sounder and repeater (an ancient thing that beeped incessantly and needed “re-tuning” every 10 seconds it seemed) which we have definitely not kept. Then of course we still have the Electrawind and Electravane wind instruments.

The Tack Tick instruments have a couple of advantages for classic yachts - they are wireless, and believe me there are already enough wires on Marelle, I think she still has wires from every generation of instruments she has carried, including her original B&G instruments - and they are solar powered, sparing the battery power that we think is in a delicate condition, at least on the domestic battery. Another job, another day...

However there is no dedicated package for classic yachts from Tack Tick. The cruising package is not right, as it doesn't include the triducer (combined log/depth/temperature), sensible to minimise the number of holes in your boat, or the bronze housing, essential for wooden hulls. And the racing package is too over the top, at least for Marelle. Martin tried to persuade the Tack Tick people at the London boat show that they should offer a package for the classic yacht fraternity, but to no avail. Too small a market, apparently.

What we ended up with, was the bronze housing, the triducer and wind vane with analogue and dual digital displays, the remote display and NMEA interface, and for fun mainly, and so I can see how well Martin is sailing Marelle, the race compass.

I now know much more than I should about wiring and NMEA.

As ever, nothing is straightforward, and for some reason the hole for the previous log, that we wanted to reuse for the Tack Tick (actually an Airmar) triducer, was mahoosive. No bother, Universal fixed it, very nicely too, and then we discovered it was also at the wrong angle.

Deadrise, or how much the hull slopes at the point where the triducer goes through, is it turns out, quite important for accurate depth readings. Makes sense when you think about it, but why did we have to tell Universal Metre Shed (now called Universal Yacht Care) this, rather than them telling us?

We ended up with a nicely streamlined protrusion on the hull, so that we could be as close to vertical as possible with the triducer.

The triducer has to be connected to the hull transmitter, which needs to be powered, although it does have a battery for back up purposes. It also has to be mounted at least 50cm above the waterline, and not in a cupboard or surrounded by any metal - although with Marelle I did want to put it somewhere reasonably unobtrusive. A further restriction is the length of the cable from the triducer - 3m sounds like a lot, until you have to route it behind and around all sorts of things. I ended up putting the hull transmitter at the forward end of the shelf in the saloon on the starboard side. This has the advantage of being partially hidden by the shelf, and is an easy cable run to the triducer, which is under the saloon table. Running a power cable across to it without taking the interior apart was more challenging. We ended up using a coax cable that was already in place, connected to a B&G(!) wiring box. At some point the wiring on Marelle is going to need serious attention I think.

Next up was the NMEA interface - more requirements here - connect to power, mount on a transverse bulkhead. I have put it next to the switch panel on the chart table, although with this and the hull transmitter I have not screwed them on yet just in case they need to be moved.

Finally the iAIS from Digital Yacht. I connected the power for this to the GPS power output on the Tack Tick NMEA interface, mainly because there was no spare power on the switch panel and I didn't want to disturb too much wiring. I then connected the NMEA input wires to the output from the Tack Tick NMEA interface. Must find some labels at some point, because currently the “Depth” switches on the Tack Tick hull transmitter, and the “Navtex” switches on the Tack Tick NMEA interface and the iAIS.

After a bit of research, I figured out that the Furuno GPS that was already on the boat, contained an NMEA output in the power cable. Checking where this power cable went into the switch panel, sure enough there were two extra wires there. Very carefully, I opened the power cable up where it passed the Tack Tick NMEA interface and pulled out the NMEA cables, and connected them to the GPS inputs on the NMEA interface.

So far, so good.

Everything switches on, and I managed to get the iPad connected to the wifi network created by the Digital Yacht iAIS easily - just going to Settings, Wi-Fi and highlighting the DY... network. There's no security on the network - guess it doesn't need it for the AIS information, but this has interesting implications with connected wireless devices (computers, ipads etc) in a marina.

Even better, using the Digital Yachts free app I can see AIS signals!!! Exciting stuff. I also splashed out on the iNavX chartplotter app, with associated UK charts from X Traverse. Got this to connect up to the iAIS too - after a bit of fiddling - but so far I haven't been able to see the instrument data from Tack Tick in either of the apps.

Really not sure why this is. I guess I need to check the connections and investigate further when I'm next on board - I'll update this post after further testing!

Update

Finally got around to re-testing this, switching everything on carefully and in sequence - first the Tack Tick hull transmitter power, then the Tack Tick NMEA interface power, then the Furuno GPS, then the iAIS, then switching on the Tack Tick instruments themselves via the remote display (you only have to switch one instrument on and it wakes all the rest up). Lastly the iPad - went to Settings, Wi-Fi and highlighted the DY... network. Started up the iNavX app, looked in the TCPIP NMEA screen and woohoo! - here is a lot more NMEA data than before.

 

So far so good. Next to the instruments screen, and hey presto! - here is all the data!!!

For reference here is the NMEA interface with the connections I made. The blue and white wire come from the Furuno GPS, and the green and yellow, and thin red and black, go to the iAIS.

Next I tried seeing what happens if I switched off various things, e.g. the Tack Tick instruments - all performed as expected, i.e. the iNavX just displayed the remaining position and AIS data.

The only thing I can think of that could perhaps have been causing the problems before, is the Location Services setting, which I now have switched off in the iNavX TCPIP NMEA client.

Now off to learn how to use the iNavX plotter!

 

Update June 2012:

After a long period of not using the instruments, I switched on the power to the hull transmitter, and nothing happened – no depth or log reading. I did have a nasty feeling this might happen, as I remembered reading that the hull transmitter contains an internal battery. The Tack Tick website claims that the hull transmitter will power off before its internal battery completely dies, so that it remains rechargable when power is applied later, and recommends to “connect it to volts” for 12 – 24 hours to allow it to recharge. Fingers crossed...