Thursday, 13 December 2018

Navigation Instrument WiFi connectivity on a Cruisers budget

Setting up WiFi connectivity on a Cruisers budget


Scouting made easier using a mobile WiFi unit to send depth and positioning data to a tablet to make/update navigation charts. I put together a portable WiFi enabled GPS/Sonar to transfer depth and position data to make a sonar chart on the fly. Personal HD depth contour charts develop in real time as your boat (or tender) moves through the water. 

On board I also connect a WiFi unit with built in multiplexer to send the AIS and Instruments data to  our navigation laptop running OpenCPN.

Scouting made easier.

Scouting new anchorages has always been a bit of a hit and miss affair. Turning up at a remote part of the planet and wanting to stop for the night would often find us anchoring in places that sometimes didn’t offer the protection we could have had if we were able to move closer to shore. These anchorages off the beaten track often lack detail on the charts we have.  Exploring new areas late in the afternoon made us uncomfortable due to the angle of sun not allowing us to see into the water easily. Getting our keel caught up with a falling tide has the potential to be disastrous.

Opppps caught on a receding tide, deep water was just to port


Potential anchorage but the chart is lacking detail

A Google Earth chart overlay can help show some detail but lacks depth information

We have tried several different methods to help quickly scout out areas we were interested in moving through. The first was a forward facing sonar, while the idea was good it turned out to be an expensive exercise. The draw back was the unit was very hands on and when we wanted the unit to be working at its best while manoeuvring in tight quarters, we couldn’t easily keep up with the setting changes to keep the obstacles on the display. Then as we were coming to grips with the operation and a couple of niggling problems, the company was sold and the new owners didn’t want to offer much support for the model we had.  So we shelved the forward facing sonar and at the next haul out we removed the transducer and unit.
Rather large forward facing sonar transducer ready to go

Talking with others the overall consensus was to get out in the tender and have a look around. Scouting in the tender did have advantages but doing the sounding with a lead line was very time consuming and had the potential to miss a bommie or sharp pinnacle. We were searching for a reliable alternative and being full time cruisers a cheap solution would be nice.

A viable alternative was to install an active depth transducer in the tender. I thought the active transducers were a good idea, apply power and they would output a NMEA0183 depth string. We already had a Garmin GPS 72H.  This unit will take a NMEA0183 input and the depth could be displayed on the screen. We could later follow the track made while we were in the tender to bring Matilda in to the anchorage. The only minor drawback to this plan was if we were scouting in the shallower places we would need to make a good run in the deep passage to make a usable track. As it turned out the active depth transducers we could find were just too expensive. So we looked at simple hand held depth reading units but they were lacking any real positioning, so there was room for error if we didn’t get it right when back on board Matilda.

We had all but shelved our plan when our local chandler was having a pre summer sale clearing out the stock of small chart plotter/fish finders. We got a Lowrance Elite 4 Chirp. The unit has a built in GPS and CHIRP transducer and due to its size it has low power draw. At the time the price was better than an active depth transducer and we have a GPS and sonar display screen in to the deal. One of the items that attracted us to this unit at the time was that we could up load (on the internet) our sonar tracks and get a chart for the area we had scouted. This sounded good but required an internet connection to upload the data and then we had to wait for the finished product. This turned out to be a frustrating exercise, but I guess it worked for the week-end fishermen who could afford to wait for the next weekend.

We could copy our sonar logs off the unit, this was in Lowrance sonar file format .SL2. Unfortunately there isn’t much you can do with a .SL2 file, the program that was previously available would no longer work with newer computers. Then we found a program that would read the .SL2 files https://reefmaster.com.au/index.php/products/sonar-viewer. While this was a step in the right direction it wasn’t exactly what we had in mind. It would however be great for fishing and looking at what had gone under the boat during a trip, however it didn’t give us the chart to navigate on.

While we were searching for the program to read the .SL2 files we saw that Navionics could make a sonar chart live. What a great tool, we could have a depth chart done on the fly in the field so to speak, no waiting no delay and no internet needed.  The only drawback was we needed to be able to get the depth data into our Android tablet that we have an active subscription to Navionics on.  This simple video on YouTube from Navionics gives an over view of the Live Chart concept https://www.youtube.com/watch?v=RzRd6MA7XV0

On the tablet is the same bay as previous, but now has depth information after a couple of passes in the tender

A close up of the depth information detail
Our Samsung tablet has a built in GPS so positioning data isn’t a problem, however there isn’t a serial connection to input the NMEA0183 depth data. As luck would have it during our last trip back to Australia we had purchased a small Wi-Fi network NMEA bridge (YAKKER). The original plan was to connect it to Matilda’s GPS output so we could run OpenCPN on our laptop wirelessly. This unit will allow applications to directly access NMEA0183 data over TCP/UDP connections. Now we can view vessel information from virtually anywhere on the vessel. The units will also transmit AIS information from the on-board AIS receiver. So if your tablet has a built in GPS and you would like to add AIS data then this may be an easy way to do it. However you will have to ensure the program (app) will recognise and display AIS data.
NMEA0183 to WiFi bridge 

As a side note; these units are great for those of us who went out and brought iPads/Android tablets then found the units do not have a built in satellite GPS receiver. In our case we didn’t realize we didn’t have a satellite GPS receiver in one of our tablets until we fired up the navigation programs away from the dock and found they couldn’t position us. Now you can run the navigation programs on the iPad/Android tablet that doesn’t have a satellite GPS, you can send in the positioning data on the Wi-Fi connection. You don’t even need an expensive GPS, a feed off your on board GPS or a hand held with an NMEA0183 output will work a treat.  

Short video of AIS on an iPad using the YAKKER https://www.youtube.com/watch?v=gFAsBM-X5-Y

Our Hook Up

The Wi-Fi network NMEA Bridge is tiny and doesn’t consume very much power. After some quick experimenting we found the NMEA output of our small Lowrance chartplotter could easily be connected to the Wi-Fi Bridge and the depth and positioning data could be sent to the Samsung tablet. The actual wiring was simple, two power wires and a single data wire connected to the Wi-Fi unit. The output of the small Lowrance Chart plotter/GPS is NMEA0183 (RS422) with 2 wires A (+) and B (-), so I simply connected A (yellow TX A) to the RX connection on the YAKKER, NMEA to Wi-Fi Bridge.

Our chart plotter uses the NMEA0183 RS-442,  both styles RS422 & RS232 of data transfer types are shown
Our hook up RS422 depicted in the previous drawing by the TX_A and TX_B

This type of connection is fairly common, most Garmin handheld would use this connection 

If I was using a battery (standalone) powered GPS (like a Garmin 72,72H or 73 hand helds) that was not powered from the same source as the Wi-Fi Bridge I would also connect the grounds together. It is best to power both units from the same source, whether it is an external standalone battery or the vessels battery bank.
If using a self powered unit I would connect the grounds together as shown here with a common ground

So back to scouting in the tender, I set about working out how we could set this all up in the tender so we could scout areas of interest. I had a water proof box and a motor cycle battery we had purchased for a running light on the tender at night. It didn’t take long before I had the battery in the box, and had wired in the chart plotter and had it connected to the YAKKER Wi-Fi Bridge.
Battery and YAKKER unit fitted into a water resistant box
To keep things simple I have a switch on the outside to turn off power to the YAKKER and the chartplotter. The only change I made to the operation of the chartplotter was in the NMEA0183 setting tab was to increase the output baud rate from 4800 to 38400. I then also set the transmitted NMEA sentences to only include GLL GGA RMC RMB and for depth information DPT and DBT. I found the shorter string of data was all we needed for the tablet. The reason I send the GPS info to the tablet is to reduce the power consumption of the tablet. I turned the tablet GPS off to conserve power and get better endurance from the battery.

Box sealed up and ready to go

NMEA0183 configuration screen showing sentences to be transfered

Sample of configuration screen
Setting up the Wi-Fi Bridge unit was simple. If you’re not tech savvy don’t let the jargon scare you away. The unit will boot up into access point mode, you will see it on your phone or laptop just like you see the free Wi-Fi connection at your local cafĂ©. Just follow the instructions in the PDF file that is sent to you when you purchase the unit. Log on to the device named Yakker with the password 12345678. Once I was logged on, I opened a browser window and using the address 192.168.4.1 and go, I was then connected to the Wi-Fi Bridge. What I did change was the SSID (username) and password. Once you change these and hit the submit button you will have to close off your connections and reconnect with the new identity.


Other than changing the SSID and Password I found the default settings did work straight out of the box when we first got going. After a couple of test runs I found that what I believe are due to limitations of the tablet I needed to increase the baud rate of both the WiFi data and the chartplotter. The reason for the change was because the read out and boat movement on the tablet was a jumpy on the tablet screen. Once I changed the Baud rate and reduced the amount of data sent from the chartplotter the update was a lot more fluid. Keep in mind I had to change the Baud rate on both the Chartplotter and the Wi-Fi Bridge so they were matched.





























































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If you’re interested in an Australian made product or products that won’t break the bank here is the web site: http://www.yakbitz.com

If you use EBay the units can be purchased from the online EBay shop. If you are an Ebay member you can get better deal, look here first due to the better price, the units are made by a small company in Morayfield (just north of Brisbane) and posted from Australia.
We are using this 2 port unit to send AIS and GPS data to the laptop running OpenCPN

We have since purchased a 2 Port, Wi-Fi Bridge YAKKER, we can feed the on board GPS and AIS into the unit and use the GPS positioning and AIS data for OpenCPN we run on the laptop. The 2 Port YAKKER does away with the need for a separate multiplexer to combine the two data streams. Best of all the cost for this set up was a fraction of the cost of imported unit/units.
Some other units from the range available


Friday, 30 November 2018

November Newsletter 2018

News from the Crew of Matilda
November  2018
Indonesian warships: 332 & 357 side by side at the navy base dock Langkawi, Malaysia. 
Ships log: 
  • November 3 we left the anchorage at Pangkor and took Matilda to Pulau Talang, so she was position to jump off to Penang. We anchored at 04 24.97N, 100 34.61E in 6.6 mtrs at high tide on a muddy sandy bottom.
  • November 4 we took the 61.3 nautical miles to Penang, anchoring in the allocated spot between Jerejak & Penang. We dropped anchor at 05 18.59N, 100 18.12E in 7.9 mtrs at low tide.
  • November 8, moved Matilda to the channel for an early take off in the morning for Langkawi. From Jerejak we travelled 8.3nm's. Dropped anchor at 05 24.18N, 100 20.68E in 7 meters.
  • November 9 we motored for 12hrs covering 63.3 nm's to Langkawi dropping anchor at Bass Harbour - Kuah. 06 19.05N, 99 50.65E in 3.3mtrs right on low tide.
  • November 21, motored for 16.4nm's around to Telaga harbour providing a rolly evening despite our stern anchor. We dropped our anchor at 06 21.72N, 99 40.49E in 4 metres.
  • November 22 we mostly sailed the 27.6nm's to Thailand's Koh Lipe. Dropped anchor in 18metres at 06 29.40N, 99.17.58E on its north facing side.
  • November 25, we moved over the other side of the channel between Lipe and Adang as a NW'stly was forecast. The journey was only 45 minutes. We dropped anchor at 06 30.18N, 99 17.92E in 7.6 metres on sand.
  • November 26, went for an explore over to Koh Butang to do some snorkeling. Dropped anchor at 06 32.12N, 99 10.10E at high tide in 13.6mtrs. Journey was 8.1nm's.
  • November 28, returned to Koh Lipe, circumnavigating Butang for a look. We travelled 12.4nm's and dropped anchor back n the north side at 06 29.50N, 99 17.70E in 16.2 metres.
A local Malay fishing boat in Langkawi. We always love the way they paint their boats with so much colour.
Crew log:
The start of November saw us leave Pangkor and head for Penang to gain our Thai Visa's. On the way to the little island north of Pangkor - Talang we managed to pick up a plastic bag on our prop and then just as we passed under the bridge at Penang we hit a rope, heard the engine change pitch and noticed our steering wheel was all of a sudden very hard to move.Once anchored at the Jerejak anchorage Bruce jumped in the yuk water and managed to get a rope off our rudder stock - geez not a good start to the trip up to Thailand.



Bruce looking on in disbelief that 2 hours into our journey we clearly managed to snag a plastic bag around our prop.
After such a long day it is always lovely to reach Penang. The island is pretty from afar and only gets better as you approach and such a great city. Going under the bridge never seems to loose that 'omg will we clear it?' feeling - but we do, every time.


Here is something we hadn't seen before....a fishing net wrapped around beacon!

Below is a quick video of Matilda going under the 'second' bridge.




We obtained our Thai visa's while at Penang. It's a simple process for yachties and this is what we did.


The Royal Thai Consulate - General building.

You need:
  • 2 passport photos (current within 6 months is stated)
  • your passport
  • your boat papers (copies for each applicant)
  • a photo copy (we did b&w) of your identification page in your passport
  • RM150 per person
  • Your applicationn form which must state Penang on the header (if you download this form on line and it states either Bangkok or Kuala Lumpar in the header it will not be accepted). If your at Pangkor marina go grab the form off Ruz at the office, she has the correct form, which states Penang in the heading.
  • Dress code: there is a sign out the front which the guard will point to stating: no thongs, no ladies short skirts or shorts, men's shorts are not to expose the knee, no singlets or skimpy tops. 
The sand is to the right of the photo, the area is saturate with local fishing boats.
We anchored Matilda at the southern end of Jerejak known as the Seagate Anchorage. Apparently you can land your tender on a jetty here, we could not work out which one to use. A contact number for Mr. Black 0194701865 is correct however he doesn't speak or understand English very well - our conversation with him was difficult. He is not always available as a water taxi either. If you want to leave your tender on the beach here and you don't mind standing in filthy mud up to your knees (not joking) at mid to low tide, then yes you can leave your dingy on the beach amongst the fisherman's boats.
Fauzi Ikan Bakar, Seagate will appear on Google Maps.

For transport we used Grab. The image above is the address you need for the Grab to pick you up and then to the Royal Thai Consulate General address. At the time of travel the charge was RM28 to the door and back to the cafe. Excellent value.

The car park of Fauzi Ikan Bakar, Seagate.
As it turned out we were guided in by a chap from the above restaurant to leave our tender beside an unused fishing boat on a jetty (which is immediately north of the fishing boats), which we were grateful for. However, the jetty was in bad shape and was a hazard to walk on. 

Looking towards the jetty this is the entrance. You have to walk to the right on the planks of wood.

To enter the gate you have to step on this piece which is very unstable and as you step on it, all the cockroaches take off.

This bit was stable.

At low tide this is almost vertical and not stable.

Good luck!

Final approach is just shocking. Our tender is to the far left.
Our thoughts on anchorages around Penang for those who do not wish to use the marina are not terrific. Your choices are the Seagate Anchorage which we anchored at. You can walk to Queensbay Mall from here, we took about 45minutes and the path is excellent. You cant get water here.

Batu Uban Public Marina anchorage which is cheap, but not easy to get in to. You are allowed to anchor out the front with permission gained in advance from rosziyana@marine.gov.my, even then you have a 24hr restriction for anchoring. Why the restriction is anyones guess, what difference does it make. You can get water here which you pay for, dump rubbish and it is secure to leave our tender here.

Then you have the Fishermans Wharf, more commonly known as The Dump anchorage (because it is directly beside the towns dump complete with the city's sewage outlet pipe) which is out the front of McDonald's. The water is absolutely foul here, your tender line in the water will make you dry retch its that bad. However you do a have safe & secure place for you tender at the unused marina. You play a game however of being locked out if the fisherman go away and remember the gate is locked everyday from 5pm so no going out for dinner here. You can not get water here, but can dump rubbish. Its a very easy walk to the local shops which are great, including a very good doctor and coin laundry.

Next stop is the Clan Jetty anchorage. The local water taxi seems impossible to get a hold of (we know this because we yelled out to the taxi guy and he wouldn't even come near us), you can no longer leave your tender on any clan jetty and access is tidal even for the water taxi guy if you can get a hold of his phone number. No access here makes this anchorage only good for an overnight stop to or from Langkawi.

The anchorage out the front of Strait's Quay Marina is fraught with danger as its exposed to the north, north west. It is also shallow in close so us deep keelers must anchor way off, and there is a lot of land reclamation work going on here with huge machinery running floating pipes back to the shore. If your willing to risk the weather coming up, it is a very good anchorage. You can pay a nominal fee for a gate key at the marina which gives you access to showers/toilets. You can dump rubbish and get water here. Loads of cafes and free buses to town.

All of the above are negative comments and we hope in earnest that the government bodies understand that all yachties absolutely love Penang and just want/need to have a safe, secure, easy to go ashore anchorage with confidence that we are safe to do and that our tender will be there when we get back. We know many yachties are already bypassing Penang for the above reasons - what an absolute loss for a great place.

As a footnote details for the above can be obtained via the Facebook group: Ahoy Penang.

As we approached Langkawi the fisherman where heading out for the night.
Approaching Langkawi we loved seeing these old 'tall ships' which no doubt are used for charter. 

The Lili Marleen

The Puteri Mahsuri
Last time we approached Langkawi we saw one of Bruce's old work boats which had obviously been sold off to a local Malay university - the vessel is still in place and looking a bit weathered. 

It's still here.
Royal Langkawi Yacht Club, protected by its breakwater wall.


A charter boat in the makings. Love her low belly to the water line.
We enjoyed our stay anchored in Bass Harbour, Kuah - Malaysia. Its a terrific spot to resupply as everything is here. You can anchor in the harbour with good depths and shelter. Its easy to see why yachters who get here extend their stay. Our stay was mostly due to Bruce waiting on parcels to complete his Raspberry Pi (RPI) installs. He has done a good write up on why we choose the RPI here and about his set up here


Amongst all these parcles is our parcel.....


And a few days later Bruce has his final parcel....wooo hooo.

Each evening we enjoyed watching and listening to two eagles as they hunted. There was an unattended ketch beside us and the eagles used one of its masts to perch on. One would always land and then call and call until his/her mate arrived.

The one of the mast is calling out to the one behind. 
Back on his own, he never stopped keeping watch.
Thought we would share the sign at the fishermans wharf (not the blue jetty) but at the creek wharf.
Once the last package had arrived we went for a break over to Koh Lipe, Thailand. It was lovely to be in clean clear water to enjoy a few snorkels and we swam every day. Went and had a look at Koh Butang, it was very nice and its big neighbour Koh Rawi has a waterfall on it but we didn't get there this time.

We were treated to a beautiful sunrise each morning.
Walking Street on Koh Lipe is an interesting place.



While at anchor at Koh Butang we had the incredible advantage of watching the sunrise over Koh Lipe.



Matilda sat so flat I was close to being able to get a clear shot as the sun rose in full.

This shot has no filter on the camera for sunrise. The colors where just gorgeous.


While the sun rose I turned around and this is the shot away from the sun, incredible difference. The water around us was almost completly still.

Once we reached Langkawi we have had a been of time to our self this month We enjoyed just chillin, catching up on boat jobs, reading, relaxing, swimming, snorkeling and time ashore. 

Thanks to the local newspaper, this shot of four water spouts was captured. We missed the four but saw one of them - not a comforting sight.

To close we remembered during this trip to take some photos of the street art in Langkawi.