Friday, November 6, 2015

SeaClear II - How To Use This PC based Navigation Freeware.

This is part of a email flyer sent out to its members

I recently volunteered to do a workshop at the Center of Wooden Boats on How to use SeaClear II which is a free ware that turns your PC laptop into a fully functioning Chartplotter. Over the last several years I have helped several sailors along the way learn to use this incredible tool. A sailor, Dean Dominique,  who had just returned from a cruise Corpus Chris to New Orleans and back took the time to teach me the software. So I enjoy paying it forward to others who may find the tool useful for their journey's. I thought it would be a great idea to just include it on my blog for that purpose, not sure why I did not do it sooner?

How to Use SeaClear II and Downloading Free US NOAA Charts
SeaClear II is an Open Source Freeware that functions as a simple Chart Viewer, Route Planner or a complete chart plotter with the addition of a USB GPS puck. In addition you can connect through USB cables to your NEMA 0183 and NEMA 2000 on board electronics allowing you to also view AIS targets, depth, wind, and radar.
 Charts can be downloaded free from NOAA or any other source like the US Army Corp of engineers for inland lakes and rivers. If you can access a chart in electronic form or even scan a paper chart SeaClear II has a chart calibration program that can prepare the chart for use in SeaClear II. Additionally whenever charts are updated by NOAA you just download the latest revision FREE!
The software is PC based but Mac users can download WINE and successfully use the software on their Mac Books. We use SeaClear II primarily as a route planning tool but it is comforting to know we have a backup chartplotter handy just in case and our total expense is just the $35.00 we spent on the USB GPS puck. I prepared this document to assist others to get started on the initial process of downloading the software, NOAA charts and a few tips on how to plan a route. The software comes with a complete manual but it is a little techie for some of us. The two stumbling blocks seem to be how to view the charts after downloading from the NOAA site and How to enable the GPS puck on your device. There is also a very active Yahoo users group for help. I enjoy passing on this valuable tool as other sailors passed it to me. Just a note, some Windows 10 users report that it is working successful on that OS.

The following are examples from the SeaClear II Screen:

Steps to Install SeaClear II and NOAA Charts:
1.    Go to and scroll down to SeaClear II Full install sc_setup.exe ~ 2 Mb. With English Manual.  (You may want to check the other options for older operating systems). When you click on the link to download the software be sure to choose “Run” on the File Download box. This will download the software into your programs folder and prepare the software for use. The software comes with a utility program called “MapCal II” that will load the NOAA charts into SeaClear II. You also get the manual, which of course is written for persons who can understand highly technical language. This is normal for Freeware but if I can do this anyone can do it! After the program has been downloaded on your computer then it is time to download the Charts from the NOAA Site.

2.    Here are the steps I take to load the NOAA RNC (Raster Navigational Charts) into SeaClear II. These are of course the most up to date NOAA charts available. So anytime a chart is updated at NOAA then you can always go back and download the latest version.

1. First I created a folder to download the NOAA Raster charts into from the NOAA website and I just named it "NOAA Charts". (I put this folder in the 'My Documents" folder but you of course can put it anywhere.)

And click on the "proceed to chart downloader" link at the bottom of the page.
4.    Click on “Here" to load NOAA Raster Navigational Charts at the top of the page. You can choose to download the charts either by the coast Guard district, State, or Region. I chose to load by state (to help me stay organized since I am not that familiar with which charts are in either CG Districts, or Regions).
5.     Click on the Blue link for the state Example: WA
6.    Click “OK” at the bottom of the users agreement.
7.    Click “Save” at the File Download Box.
8.    In the “Save As” box choose the folder "NOAA Charts” that you previously created in step 1 in the "Save IN" window and then click "Save" at the bottom of the window. This will download every single Chart from the state or region you selected as a “Zipped File” (Zip files allow for faster downloads for large files and for example Florida has 85 primary charts with over 100 sub-charts for bays and rivers). Can you imagine not only buying all these charts but also storing them? . I suggest you do this process for one state before downloading more so that you can get the hang of it. If you want to just download an individual or small area of charts they can be accessed at Just follow the onscreen instructions for downloading individual charts. If you need help downloading individual charts see for an explanation.

9. You get a zipped folder downloaded with all the state, regional or individual charts so you have to unzip or “Extract All”. Put your curser on the downloaded zipped folder and Right click on the downloaded zip file. Select “Extract All” This places a unzipped folder in the same location. Open the unzipped folder and you will see a folder named BSB_Root, open this folder. You will see all the folders with the chart numbers as names. Open the first one and you will see one or more (KAP) files. These are the charts you need to individually drag into the Charts folder in the SeaClear program files. You will need to do this for each file folder. There may be a quicker/easier way to do this part but I have not figured out how to simplify this. (If you figure it out please let me know!) I copied the following from the users manual:

Installing BSB charts
The BSB/KAP file format is licensed from Maptech. BSB/KAP version 1 – 3 is supported. Projections
based on Mercator, Transversal Mercator, Polyconic, Lambert Conformal Conic, Sinusoidal and
Orthographic are currently supported.
Charts are available for most areas of the world from Maptech, NDI and many other sources. The
actual chart is in a KAP file, while the BSB file only contains data regarding coverage and similar. As
SeaClear keeps it’s own database, the BSB files are not needed.
Before using BSB/KAP charts in SeaClear they should be registered:
Start MapCal and make sure all KAP files are in the chart path.
From the top menu select “Tools-> Autoload list-> Scan for New Charts”. The KAP files will be
scanned for name, coverage and other data and listed in the SeaClear autoload database.

So this is how I learned to deal with the above instructions:
1.      I goto the start menu and open "My Computer" 
2.      I open the Hard drive and goto the "Program Files" and open it.
3.      Then I open the "SeaClear" folder.
4.       Then I open the SeaClear "charts folder.
I minimize the window with the NOAA Charts folder right next to the SeaClear Charts File folder open next to it and I individually open each of the chart folders and drag ALL of the “KAP” files into the SeaClear Chart folder. This is the most time consuming part, for Florida it can take 30 minutes to do this Tip: Select all the KAP files in each folder and drag the whole group into the SeaClear chart Folder.

Do this for every downloaded chart file. For Florida there are approx 85 folders you have to individually open and drag the files over to the SeaClear Chart folder. ( I know there must be a easier way but I have not found it yet).
If you need a Chart Catalog goto:

5.      After you have the KAP files in the Seaclear folder then go to Start then All Programs then SeaClear and open the MapCal II program. Goto the tools menu and then Autoload List. Select “Scan for New Charts” this will load all your charts into SeaClear II and you are ready to go.
6.      Open the Seaclear II program; from this point forward it is best to use a mouse to Navigate SeaClear II. You can use the touch pad on a Laptop but it is slower and more cumbersome, a mouse with the little finger wheel makes it a snap. The finger wheel on the mouse will allow you to quickly Zoom in and out on the Charts. The first screen on the SeaClear program is a chart of the world, just zoom in and click on the area of the state you want to view and the appropriate chart will open OR goto the File Menu, select chart, then List All. Here you get a list of all the charts you have downloaded and select the one you want.
7.      It would take a while to write out all the features of this software so please refer to the Manual that comes with the software, just go to the Start, All programs, SeaClear II and select the Manual. But just to get you Started Goto the Tools menu at the top of the screen and select “Route Editor” Just for fun using your mouse goto anywhere on the chart and double click, then move a few inches away and double click…this is how you build your routes, you can easily change your waypoints on the chart by either dragging them to a new location or right-click on them to delete, add a new point between any two established point…just play with it and notice the side bar on the right, as you build your route it gives you distance and other data. After you build your route be sure to save it, you can always call it back up and edit it or use it over and over again, you can even email it to your friends.
One more excellent feature is when your route extends beyond the boundaries of the chart just move your cursor to the edge of the chart and right click and select “Best Chart” The adjoining chart automatically opens and you just continue to build your route. Just think if you have a friend that is following behind you a few days you can email him your routes and he can easily load them into his SeaClear. So I have all my routes from Corpus Christi to Miami, FL. and I can just email them to anyone.

Lastly you can make SeaClear II a Chart Plotter by simply adding a USB GPS puck. This is the one I use and it works perfectly: So for a couple of hours learning how to use SeaClear II and $26 bucks you have a chartplotter with the latest NOAA charts that you can always update for FREE. You can goto to check on updates. In the event something happens to my primary chartplotter at the helm I always know I have this as a back up system. If you need a driver for the GPS puck goto

If you connect your computer to your NEMA panel then you can also get depth, AIS, Speed, Wind, data on the Chart viewer screen, See Page 7 of the SeaClear Manuel.

Link to the Yahoo Group SeaClear
Mapping: I joined this group and and it is a great place to learn how to use the full use of SeaClear. _

Q & A From the Yahoo SeaClear II Group:

Dave Gilroy wanted to include the interior river system charts that are available through USACE as PDF files. These files can be converted either by scanning the paper charts and saving them in formats compatible with SeaClear or by using online file conversion software. See Dave’s Notes:
“I  had to convert the USACE PDF file to a BMP file with a  free online converter in order to load the chart into Mapclear.  I was then able to convert it to a WCI file, calibrate it and load it to Seaclear II.   I have something wrong with the scale of the chart but I ran out of time last night so I am going to work on that today. 
There is also a site for USACE electronic charts but they are in an S-57 format and downloaded with as an ENC file that is not recognized by Mapclear.  I did not have time to try to convert them to BMP or WCI files but I will give that a try when I get the time. is the website for these charts.”
 Managing Com Port of GPS Puck
For seaclear cannot find com port in win 7, 8.1.
Open  < control panel>
Plug in your GPS. 
Start seaclear.
If it says cannot find com port number #
Check which number com port the GPS is connected to.
Change com port setting in seaclear to the same number.
Restart seaclear.

Please be informed that Windows 8 or 8.1 typically requires a different USB driver for the GPS. In some cases you might be able to use the old GPS with Windows 8 or 8.1 in compatibility mode, but not always. For instance the commonly used GlobalSat BU-353 (SiRF III) GPS does not work with Windows 8 or 8.1. Instead there is a new version of the same GPS mouse called GlobalSat BU-353S4. So it is not at all self evident that you will be able to use your old GPS with Windows 8.1.
you might need to lock the com port to the device
plug the device in
goto windows device manager
find the device
right click to get to the properties
goto port settings
click on the advanced button
set the port number you want to always relate to that device.

 Thank you Paul, I am glad the antenna works well. Good that you can feed in instrument data as depths is particularly useful on the river.
Date: Wed, 5 Feb 2014 15:34:11 +0000
Subject: [seaclear_mapping] Re: Laptop use with BU-353S4 antenna.

There's a really good explanation of how to use your Sea Clear software in simulation mode here
Which will let you learn to use it at home without a GPS signal.

I also have a BU353 antenna, it works well. Plug in and it will install the drivers.
Go to Devices and look at the Prolific USB to Com device and note the Com port
Start Sea Clear, go to Tools > Properties > Comms tab. Set one of the RX ports to match the com port number and the baud rate to 4800 and you're good to go. If you plug the antenna into a different USB port in future you'll need to repeat this procedure.

I also feed it NMEA AIS and instrument data from my instrument systems, again just configure the port and rate and it worked.

Hi, I am running Seaclear II on a netbook with Windows 7 and a BU-353 gps receiver. The position displayed on the chart appears to be off by at least 50 feet. I am using NOAA charts imported to Seaclear using MapCal. Does anyone know how to correct this problem?
 Check you chart datum against gps datum. North of Vancouver Island as example uses NAD 1933 or simlilar and yields about 200 ft difference from NAD84. 
Thanks for your reply. 
I checked the Latitude and Longitude data reported in Seaclear against my Garmin and the Latitude is right on but the Longitude appears to to vary slightly ( .005' to .010' ).
I just found how to set the GPS Data to NAD 84,
I went to Tools_Properties_Comm Tab and changed the GPS Setting.
I was set on North American 1927. The chart says either would work 
but now the data on Seaclear matches my Garmin within .001'.
I'll test this new setting on the lake this weekend.
Thanks for the information that got me digging!
Using a Garmin handheld as the GPS source for SeaClear II
Just closing this topic out for anyone who may have similar problems in the future. I use a TrendNet TU-S9 serial converter to go from the 9-pin on the Garmin handheld to the USB for my laptop. It turned out windows/SCII didn't really care about a Garmin handheld driver, it wanted a driver installed for the TrendNet USB device.
Installed the driver. Everything working fine. 

Using SeaClear II on Tablets

WalMart is selling a “Nextbook Flexx 10” 2-in-1 for $165. It’s a 10” Windows 8.1 laptop who’s screen detaches to be a touchscreen tablet. It has two full size USB ports in the keyboard, and a micro USB port in the tablet part.
Unusually for a tablet, the charger is not the micro USB, but a separate 1/16” round pin jack. This lets me use the micro USB for the GPS dongle and have the tablet plugged in at the same time.
Control Panel identified my GPS-360 dongle as Com 3 with no fiddling or driver loading at all. (I did of course have to buy a full size USB to Micro USB adapter for $14.99)
SEaClear s running perfectly on this. Thee screen isn’t really daylight bright, but it’s usable outside in the sunlight. I’m running up a holder with a screen shade to try to improve it.

Connecting SeaClear to Onboard Electronics

Paul Smith [seaclear_mapping]
Mar 12
It works for me, Raymarine ST60 instruments feeding C80 and Brookhouse Mux. Mux out via USB to SeaClear gives consistent wind speed readings between Raymarine and SeaClear

Is there a Serial to USB Driver available?
Yes there are USB to serial to adaptor and driver. I searched on EBay and bought a single one. After setting up my PC nav system I realized I needed a 4 port one. I think I also ordered it from EBay, along with DB9 breakout boards to hook the wires to. I send and receive data from my AIS-VHF radio and send data to my Autopilot. It was a bit of a challenge getting all the stuff to work, but it does, and has for 3 years.

Adding AIS to SeaClearII

Op 3 aug. 2014 13:41 schreef "J Corsican [seaclear_mapping]" <>:
What's the easiest and cheapest way to add AIS to Seaclear?
1. Buy AIS receiver with USB output.(no need for serial output)
2. Buy USB 4-port extension hub and plug in laptop.
3. Connect the AIS receiver, mouse, keyboard and GPS USB puck to hub.
4. Configure the second Rx port in Seaclear-tools-properties (comport nr - see windows device mgr)
5. Configure baudrate as 38400 

Converting Tracks to Routes

You can convert a track to a route in SeaClear:
Tools => Route Editor => File => Route => Import Track
Then you can edit the route on screen and save it for later use.

Using a MacBook Pro for Seaclear II
Yes it can, if you install WINE first. I have it running fine, although I have not tested connecting it to a GPS, but I think that should work OK.

However, WINE is a bit techy, so you need to be familiar with using the command line interface to your Mac, accessing the Unix Operating system beneath. WINE lets you run Windows software on an Intel Mac from within MAC OS. It actually works on most Unix operating systems, e.g. Ubuntu.

It is very convenient, as you don't have to reboot your Mac to use it, you just click on an icon as usual. I run the Windows version of MS Word and Excel very successfully under WINE as well. I'm afraid I installed WINE years ago, so can't remember how I did it, but I would have searched Google for the instructions.

Do a Time Machine backup before starting, and if you make a complete hash of it, you can always revert to a backup.

I should say though, that I favour buying a cheap old robust laptop PC running Windows XP for use aboard the boat, dedicated to SeaClear. Do you really want salt water over your Macbook? Also, every addition of complexity always bites you back when seas get rough and you feel a bit seasick! My laptop always works flawlessly in harbour and goes wrong when I really want it to work :-) I've even replaced the hard drive with an SSD drive, in case it was the slamming of the waves that was causing the hard disk to complain.

But for route planning at home, SeaClear on a Mac is lovely. I keep my route and track files in Dropbox so they are automatically synchronized between my Mac and the boat's laptop. Plan route at home on the Mac, upload from PC laptop to GPS when on board.

For my Blog Readers:

If you decide that you want to use SeaClear and run into any issues you can easily get my attention by joining the SeaClear II Users group on Yahoo. If you post a question there I will surely see it and get you a response right away along with several other users as well!
Happy Navigating,

No comments:

Post a Comment