Image Logs   Back to Terry's Articles     See UPDATE below.


Log keeping is a necessary element of seamanship.  The official log is the history of passages, sometimes playing a vital role in disputes, and bears requirements for record keeping that are minimal but don’t always give you that recall you are looking for years later.  So the log becomes annotated with comments, drawings, photographs … whatever you desire.


But log keeping underway can become a chore, especially on a short handed vessel.  Manual entries then tend to meet the minimum – position, course and speed at intervals, weather conditions, vessels ‘spoken’, course changes, and the like.  But when the wind is howling, the boat is rocking and you’ve been up for 20 hours in rough conditions, log keeping tends to become a burden but, perhaps more than ever, a vital requirement.


On VALHALLA we have begun to use electronic charting, with GPS, to assist in navigation.  Paper charts are also kept handy and the minimal information plotted in case of total electronic failure such as in the unlikely event of a lightning strike.  That’s also the reason we carry a sextant and the tools to find our position ‘the old fashioned way’.  This ‘old fashioned’ tool in our bag of tricks is another reason Ocean Navigator®, with a promotion of celestial navigation, is the only sailing magazine to which we subscribe and don’t mind paying the postal forwarding fees.


With a laptop computer running our favorite electronic charting program, Sea Clear II®, I find the display of our position and all of the attendant information quite useful.  Also, I have developed the technique which I call ‘Image Logs’ to instantly record this plethora of screen information.


Using the ‘print screen’ command, the screen image is pasted to the computer clipboard.  Note that this technique works only with programs that do not require a screen display of 256 colors, such as CMAP.  I use the Corel® Photo-Paint program to import the image from the clipboard then export it, sometimes with annotations, to a daily folder under the time the image was taken.


UPDATE: Since this technique does not work with programs requiring a screen display of 256 colors, such as CMAP, I now use a shareware program called 'Snag It' (  This program is very easy to use.  It can be configured to save any screen image to a predetermined file with just the press of one user-defined key.  I now use the Snag It program exclusively for my Image Logs and have found it to be useful for other purposes such as capturing screen images while surfing the Internet.


The following (Fig 1) shows an example of an underway image.


Fig 1



The route (thin red line) and the vessel track (heavier blue line) lead to the vessel’s position shown by the red circle.  In the upper right hand corner the position, course over ground, speed over ground, UTC, log distance, trip distance, and trip hours are all displayed for this time of 1500 LMT on 26 October 2004.   The position, azimuth and distance displayed in the lower right hand corner pertain to the current location of the cursor.


Note the time and date displays on the screen.  The one in the upper right hand corner is GMT and is displayed by the HaoSite Time shareware program ( The time on the screen with the date and day information is from a free program called Topmost Clock and is available at  This handy clock display can be moved anywhere on the screen and has a variety of displays.


Another use of the Image Log is for an event such as a course change.  One is shown here in Fig 2.


Fig 2


Note that the event “Course change to Halsey Harbour” has been added to the image using the text tool on the Photo-Paint program before it was saved.


Finally found that good anchoring spot?  Fig 3 is an example of searching around and then putting the hook down at a suitable location.  Those depths are in meters so you can see why it took some looking   Once you’ve found a good place just take an image and save it. Now you not only know, and can show to others, where you anchored but also where not, which is sometimes just as important.  Annotations regarding anchoring depth, bottom conditions and the like are quite useful in the future.


Fig 3


Remember those rough conditions I mentioned?  I confess to recording Image Logs during the time when hanging on and writing are extremely difficult then catch up on the official log when the situation is more amenable to writing.  Also, a very handy item to use at any time, but especially during rough weather, is a trackball instead of a mouse or those terrible touch pads which don’t like moist fingers.  With the heel of the hand firmly holding the trackball only the fingers need to be moved to drive the machine.


We maintain a website called Valhalla’s Mooring Page ( and under ‘Valhalla’s Adventures’ are examples of using the Image Logs in more expanded ways when describing our passages.  I’ve used inserts of photos and other screen shots to enhance the images.  On one such occasion we sighted the International Space Station and were able to record the event by adding an image of the Satellite Tracker program ( displaying the satellite passing overhead.


What you find interesting to record is limited only by your imagination.  The ease of making an Image Log will tempt you to do more.