Thursday, 23 April 2015

GoogleEarth KAP library for OpenCPN and SEAiq

Hi everyone,
For several years I have been creating and swapping GoogleEarth imagery for use in the free chartplotter OpenCPN.  The imagery is captured using GoogleEarth and GE2KAP while online and produces KAP files for use offline in OpenCPN.  Perfect as an extra aid to navigation in poorly charted areas, as described in my 2012 post here.

All the imagery I have created and which I have collected from others is intended to be shared.  I have shared on an individual basis so far.  The data is now available online.

The library is on Dropbox here.

For those who return to the library looking for new or updated information: click on the "Modified" column heading in Dropbox.  This will sort the files by modification date with most recent at the top.

First download and store somewhere safe the file "_readmefirst.txt".  Keep it for offline use.  The contents of the file are below since it provides much of what I need to explain here.  Please read on!

                               A Guide to using 
                     Zen Again's Dropbox KAP File Library
                        for use with OpenCPN and SEAiq

Origin and Further Distribution
The KAP files in this library have been generated by various cruisers 
including myself.  All who have provided files to me have indicated their 
willingness for me to distribute them further.  The only proviso we make is 
that they be further freely shared to assist other cruisers.

Intended Applications
The KAP files have been tested in OpenCPN and SEAiq using the latest versions
available at the above date.

File Naming
The ZIP files are named in the following formats:
A. <Region>_<Country>_<Locality>.zip or
B. <Australia>_<State>_<Locality>.zip

File Size
The KAP files are split into modest size ZIP files for two reasons:
1. To allow the selection of specific KAPs of interest without having to 
   download large files.
2. To allow for use in SEAiq which (since it runs on tablets) could be 
   slowed dramatically if many hundreds of KAPs are loaded.

For those with pre-existing OpenCPN chart folders such as:
  MacOSX:  /user/Shared/charts/opencpn/ge/<region> or 
  Windows: /Users/Public/charts/opencpn/ge/<region> where region is Asia, Indian etc
simply add to (or replace) the existing contents with the contents of the 
ZIP files you download here.

For those with pre-existing SEAiq chart ZIP files simply add my zip files 
nearby and use iTunes to add them to (or later delete them from) SEAiq. 

Using KAP Files
See the following blog posts:
Using GoogleEarth Imagery for Marine Navigation

Making KAP Files

GoogleEarth Imagery on iPad

GoogleEarth Imagery on Raspberry Pi

The library will be updated from time to time.  Individual files may be updated 
so check the date stamp of files you use.  New files may be added so check for 
new files in your region of interest.

If you would like me to add your images to this library just let me know.

GoogleEarth images FADE TO BLACK a few hundred metres from land!!!


Now to add some help for installing charts in OpenCPN and SEAiq.

Installing and Configuring in OpenCPN
  1. Download all the ZIP files of interest from Dropbox - usually to your downloads folder.
  2. Identify where your existing charts are located (Shown in OpenCPN in Options => Charts => Chart Files.  [I locate my KAP charts in /Users/Public/charts/opencpn/ge on Windows and /Users/Shared/charts/opencpn/ge on Mac OS X]
  3. If they don't already exist, create folders for regions (eg SEAsia, Australia, IndianOcean or similar) in the folder you intend to use for your GE imagery.
  4. Unzip (on Windows use right-mouse-button => Extract To) each of the downloaded ZIP files to the appropriate region folder.  Unzipping will create a folder for the <Locality> described in the readme file above.
  5. Check that your folder structure looks something like "charts/opencpn/ge/Australia/Abrohlos" with .kap files in the Abrohlos folders.
  6. If you wish you can add an extra layer of folders to fully mimic the file naming structure in the readme.  This depends on how you wish to use Chart Groups - read on!
  7. In OpenCPN go to Options => Charts => Chart Files.
  8. You should see a list of chart folders OpenCPN is using, often including a folder "CM93".  If you have some KAP files already loaded then there should be another folder.
  9. Click the Add Directory button, browse to the folder where your new KAP files exist, highlight the folder then click on Open.  I suggest highlighting the region folder (eg Australia, SEAsia etc), not the locality folder (unless you want a Chart Group for each locality).
  10. Tick the "Force Full Database Rebuild" switch and click OK.  OpenCPN will then scan all your chart directories building its chart index database, which may take a minute or three.
  11. When the rebuild finishes, zoom way out (using the "-" key) so you can see the regions covered by your GE imagery.  You should see small red boxes which show the location of each image.  If not go into Options => Display, turn on Show Chart Outlines, click OK and look again.
  12. To view a GE image zoom in over one of the red boxes and centre it in the screen.  At the bottom of the OpenCPN window you should see blue "tabs" appear to the left of the yellow tab which was there before.  The rightmost tab is always the real (vector) chart.  Others are image (raster) charts.  Click on the leftmost tab to open what is usually the best image for the location.
  13. Sometimes OpenCPN zooms when you change from one "tab" to another.  IMHO this is a bug.
Configuring Chart Groups in OpenCPN
  1. Go to Options => Charts => Chart Groups.  In the Chart Groups panel you will see an All Charts tab.  We are going to add more so that the number of GE images OpenCPN is dealing with can be controlled despite them all being installed.  I usually define Chart Groups for a region of the globe (SEAsia, Australia etc).
  2. To create a Chart Group click on New Group and give it a name (for example GEseasia) and click OK.  Then click on your vector charts (often CM93) folder and click Add.  Click on the relevant GE chart folder and click Add.  You may wish to create a Chart Group called CM93only with no GE folders included.
  3. When finished click OK to exit Options.
  4. In OpenCPN zoom way out (using the "-" key) so you can see the regions covered by your GE imagery.  You should see small red boxes which show the location of each image.
  5. Right mouse button, move over to Chart Groups and right into the list of groups.  All Chart Groups is probably ticked.  Click over another group and you should  see a set of red boxes disappear.  Chart Groups are a nice way to manage what images are accessible.  Once familiar with all this you can turn off Show Chart Outlines since drawing them seems to keep OpenCPN quite busy.
Installing and configuring in SEAiq
  1. Download all the ZIP files of interest from Dropbox to the computer you use to sync your iPad - usually to your downloads folder.
  2. Identify where your existing charts are located.  [I locate my KAP charts in /Users/Public/charts/opencpn/zip on Windows and /Users/Shared/charts/opencpn/zip on Mac OS X].
  3. Connect your iPad to the computer and let it sync if it wishes.  Open iTunes if it doesn't open automatically.
  4. Click on the iPad symbol at top left of iTunes, then click on Apps on the left.
  5. Scroll all the way down past the Apps list to the File Sharing list.
  6. Click on SEAiq Open in the File Sharing list on the left.
  7. On the right you now have a SEAiq Open Documents list which may be empty.  At the bottom of the list click on Add.  Browse to the folder containing the downloaded ZIP files.  Select those you wish to install in SEAiq and click Add.  You will see a progress bar at the top of iTunes.
  8. On the iPad open SEAiq and click on Charts at bottom right.  Wait for it - the response can take a few seconds if you downloaded ZIP files containing hundreds of images.
  9. When the Charts page loads you should see a row for each ZIP file, with each showing its size and number of KAP (image) files it contains.
  10. Now you see the logic behind the file naming scheme!
  11. Note that you download CM93 charts in a similar way, just select your CM93 ZIP file in iTunes and Add it to SEAiq.
  12. Click on Navigate and pan/zoom to the locality of the imagery you transferred.  You should see faint orange boxes delimiting the images.
  13. To change between vector (CM93) and raster (KAP image) charts click on the Settings tab and and move the slider on the Raster line in the Charts section, then return to Navigate.  You may need to pan slightly to have the page redraw.  Hey Presto!
  14. ZIP files can be removed from SEAiq in either iTunes or on the iPad directly in the Charts page. 
Hope the above helps you install the imagery.  Let me know if you like it and if you want more.

Here are two screenshots from SEAiq showing Cape Vlamingh on Rottnest Island WA.  Breaks on the reefs are clearly visible.
GE image of Cape Vlamingh, Rottnest Island, WA in SEAiq
Chart (decluttered) of Cape Vlamingh, Rottnest Island, WA in SEAiq

Monday, 20 April 2015

Mainsail Sea-Trial and Cruising JaM

Hi everyone,
On Sunday we took Zen Again for a sail.  First time for ages since we've been so busy refurbishing the galley, working etc.  We had a great sail in 10-15 knots of easterly breeze.

We left FSC with an hour to kill so we sailed north into Gage Roads to take a look at Rainbow Warrior.  She has in interesting rig.

Rainbow Warrior at anchor in Gage Roads
The new mainsail sets very nicely.  Given that Zen Again is well loaded down with cruising gear we felt she went very well.

The new tiller also had its first sea trial and is marvellous.  Much more comfortable helming with the s/s "hoop" on the tiller.

New mainsail
We joined the Cruising Section's Jib & Main "race" in a fleet of about 8 or so boats.  JaMs are fun, especially when the first boat reaches the end mark and everyone turns back.  Makes for an exciting finish as everyone closes up.  We finished mid-fleet and were happy with that.
Divided Sky and Anki
Not Negotiable

Friday, 17 April 2015

New Mainsail Arrival

Hi everyone,
Our new mainsail arrived quicker than expected and our spare time has been used bending it on and running new (longer) tack and clew reefing lines.  The sail (from Extreme Sails) looks great.  Happily we've had almost windless early mornings.

Full main - looks fast!
 We expect to sail with one reef from about 20 to 35 knots or so.

First Reef
Above about 35 knots we'll use the second reef.  This is the same size as our trisail but much easier to set.

Second Reef
The sail hoists and falls more easily than the old thanks to the roller slugs. And it just about fits in the boom bag.  I'm sure it will fit more easily as its initial stiffness eases.

Can't wait to try it out on the water!

Wednesday, 15 April 2015

CM93 Charts and GoogleEarth Imagery on iPad

Hi everyone,

!!! NOTE !!!
From SEAiq version 4.0 (released December 2015) CM93 charts are no longer supported.

On Zen Again we have been using CM93 vector charts and KAP raster "charts" (produced from GoogleEarth imagery using GE2KAP) in OpenCPN as an aid to navigation.  See our blog from 2012 on the latter.  Ever since then we have been under the impression there was no software to present this information on our iPads.  During our cruise through SE Asia we found no-one who knew of such software.

Today we discovered we were all wrong!  Thanks Carolyn for pointing us in the right direction.  There _is_ an app which can display CM93 and KAP charts on iPad.  SEAiq is the answer and it is brilliant.

Within minutes of downloading and installing the app I had installed our CM93 charts.  A few minutes later I had a few KAP files installed too.  Once aboard Zen Again it took only a few minutes to configure SEAiq to accept AIS, GPS and instrument data from our Vesper XB-8000 AIS over WiFi.

The two screenshots below show example KAP and CM93 views, both of Direction Island in the Cocos-Keeling Islands.  Changing between the two involves switching one setting (Raster Charts On/Off).

KAP file GE image of Direction Island (Cocos-Keeling)
CM93 chart of Direction Island (Cocos-Keeling)
The two screenshots show the presentation of CM93 charts in Fremantle with WiFi data enabled.  The Status Bar the top of the screen is now populated, Zen Again is the black ball and AIS targets are shown.
Success and Fishing Boat Harbours close up
Here's another view with CM93 chart detail set to "Basic".  This reduces clutter to make AIS targets clearer.
Simplified CM93 View of Fremantle and Gage Roads
SEAiq has a good table view of AIS targets.  The information page for each target is very detailed.

AIS Targets Page
Individual AIS Target Page
SEAiq also supports email requests for and display of GRIB files.  It will generate an email request to send to SailDocs.  It would be nice to see the range of GRIB providers expanded.

Weather Page
SailDocs GRIB Request Email
I later loaded a set of several hundred KAP files.  This wasn't as straight-forward as I had hoped but I eventually got them all installed and working.  I used iTunes to transfer both CM93 and KAP files.

The two issues I have found so far are:
  • Some zip files containing kap files are not accepted by SEAiq, despite successfully loading the same set of files individually
  • Unsurprisingly SEAiq gets a little slow if a large set of KAP files is loaded
Update (20 April):  The zip issue has been identified by SEAiq as the presence of Mac OS X hidden files in zip files.  These files have names like __MACOSX and .DS_Store and can be searched for in zip files using the command [unzip -l <filename>] (without the square brackets).  If such files are found use the command [zip -d "__MACOSX*" "*.DS_Store*”] to remove them from the zip file.  The next release of SEAiq will ignore these files.

It is surprising that SEAiq is not listed when one searches for "marine navigation" in the App Store.  I think that explains why we've never heard of it before.  I have mentioned this to the SEAiq folks.

Update (20 April):  SEAiq will be listed under "marine navigation" from its next release in the App Store.

One thing's for sure - SEAiq is a very useful iPad app for sailors who need their charts supplemented by GoogleEarth imagery.  It is a very nice chartplotter generally, but the support for both CM93 and KAP charts sets it apart.  Very cool.

Tuesday, 14 April 2015

New Mainsail

Hi everyone,
With the Galley Makeover set of blogs complete I can now describe other work.  The other big expense we've been looking into has been a new mainsail.  We are very happy with the yankee headsail made for us by Extreme Sails in December last year.  We decided to have Dubbo and Carl make us a new main.  Like the headsail it will be constructed from 8 oz cruising laminate.

New mainsail under construction
Our old mainsail is approaching 10 years old.  It is a very nice sail built by Hood and with an area of about 28.5 sqm.  Other than its age it has one major flaw - only two conventionally sized reefs.  We eventually decided that our cruising plans demand a main which can be reefed down to trisail size.  Since the boat is setup for two reefs we knew we wanted two reefs in the new sail - but very deep ones.

Initially the concept was to have a conventionally cut sail with less than full hoist.  The full new sail would have the area of the old sail with one reef - about 24.5 sqm.  Its first reef would be equivalent to double-reefed and its second equivalent to triple-reefed.  This would have worked but would have left us underpowered in light airs.

With a bit more thought we realised that with less than full hoist we could add additional roach to the sail.  This recovered most of the area lost with a shorter luff and conventional roach, giving us 26.5 sqm.  So with the extra roach the new sail will only be have 2 sqm less than the old, but will have the deep reefs we need.

Full size sail with extra roach
Double-reefed to trisail size
The new sail will have full-length battens like the old sail.  However it will have slugs with rollers to reduce friction when hoisting and lowering.  The rollers run up the aft face of the mast, which is happily suitably flat!

Roller Slugs
The sail's leach cord will run from the clew to the head and down the luff, allowing adjustment at the tack.  Much better than trying to adjust it at the clew.

It will be interesting to see how the boat performs with the new sail.  The centre of effort will be lower, reducing healing moment.  The centre of effort will also be further aft, increasing weather helm.  She has always had minimal weather helm when beating, particularly in light airs.  A little more may well be an improvement.

Looking forward to receiving the new sail in a few days.

Galley Makeover - The End

Hi everyone,
The new galley is now fully operational.  Here are the pictures...

Overall view
Aft worktop with large fridge lid and outboard locker
Forward worktop with sink and outboard locker
We're very happy with the result which is a big improvement.  The fridge is working very well and the new sink is great.  The expansive worktop space is a wonder.

There are a couple of jobs still to do.  A "smart controller" has been ordered and will be installed.  It will give us a readout of the fridge temperature and will automatically control compressor RPM.  At present the compressor is either full-on or off.  The other job is to fit catches on the three locker lids.

Here are the overall project statistics (all approximate)...

  • Duration = 2 months
  • Effort = 120 hours
  • Cost = $3000 (sink, fridge unit, insulation, plywood, aquapanel, epoxy, glue, paints, hose etc)

Not too bad for a fairly comprehensive galley makeover!

Friday, 3 April 2015

Galley Makeover - A Fridge is Born

Hi everyone,
This week our new fridge was brought to life.  We enlisted the help of John from Bluewater Marine Refrigeration to commission the system.  John didn't have much to do, but what he did was very important.  He connected the evaporator plate to the condenser unit and checked operation of the system.  He also provided helpful advice.

On Sunday we manouevred the evaporator plate (with its 2m tubing!) into place.  That was scary but we managed it without damaging the paintwork or the tubes.

Evaporator plate installed
Evaporator plate mounting screws attach (through paint and thick epoxy)
 to plywood panels in the walls
On Monday John visited and connected the tubes to the condenser unit.  The unit is mounted in our large cockpit locker which is immediately behind the fridge cool box - on the other side of the bulkhead.  The condenser unit sits on a custom made s/s shelf.

Condenser running (note the frosted tube)
Condenser and shelf
The commissioning went very smoothly.  We were initially uncertain if the cockpit locker would be large enough to avoid the condenser running hot.  So far there's no sign of the locker warming up, but if it does we have a plan to circulate air from the lazarette which has a vent to outside air.

For the rest of the week we have been working to trim the three locker lids to size.  They could only be trimmed when painting of the lockers was complete.  Two of the lids are simple plywood and aquapanel sandwiches, while the fridge lid also has 50mm of XPS insulation.  The larger lid and the fridge lid will both have thin foam attached to form a good seal.

Locker lids (painting of edges still to be done)
Fridge lid
The fridge has been running all week with the top covered by an (ill-fitting) plywood off-cut and towels.  It is running less often and for shorter periods than the portable car fridge, and should run even less when the insulated lid is in place.  There's room for more food, more beer and even a couple of bottles of champers.  It's all looking good.