Keeping a log of the vessel’s position, progress of the voyage and circumstances such as weather conditions is not only good seamanship, a detailed logbook is often mandatory and required by the authorities for sighting after an ocean voyage through international waters.
The traditional method of keeping a hand-written logbook can be an unwelcome chore, especially in heavy weather and during short-handed passages. There are computer applications available for maintaining an automatic log book, sometimes as an integral feature in navigation software, but in spite of the fact that many ocean going vessels have a computer on board,
it may be switched off to save battery power. Also,
computer reliability can be impaired due to the harsh operating
environment. Computer-based log books often require some degree of manual interaction, which can be difficult in heavy weather. Anyone who has tried to work with a computer in gale force winds on a small boat knows that this is not an easy task.
At Brookhouse we have listened to the regular requests, received over the years from seafarers, to create a dedicated, reliable device for keeping a fully automatic ship’s log. Simplicity of operation was a key requirement. We’ve taken the proven hardware of our rugged data logger for bathymetry and created the “eLogger”. The end-result is more than just an electronic logbook, we have added a number of extra features that make the eLogger a useful device on different types of vessels, and suitable for various commercial applications. The eLogger can be easily customized if necessary.
- Long-distance cruising
- survey vessels
- fishing vessels
- any other vessels for which
an automatic, accurate log is required.
Summary of functions:
NMEA 0183 data from GPS and instruments is input via 2 ports. NMEA sources can be single instruments, output from integrated instruments or combined NMEA output from an NMEA 0183 multiplexer. The port baudrates can be set to 2 x 4800, or 1 x 38400 and 1x 4800. In NMEA2000 systems, an N2K-NMEA 0183 converter can be used. An engine on/off sensor wire is provided for recording engine running status and time.
All relevant data is extracted from the input data stream(s) and is recorded in
industrial grade flash-memory at user-selectable time intervals in minutes.
The standard capacity is 512MB, sufficient for months of recording. The recorded data includes (if available):
UTC time and date
GPS position (lat/long)
Course over de ground (COG) and speed over the ground (SOG)
Heading (electronic compass, can be fluxgate compass of auto pilot)
Relative wind speed and wind angle.
Engine running time & running status.
Water surface temperature.
In addition, the eLogger software calculates ground wind speed and direction from AWS, AWA, heading, COG and SOG. Wind speed is recorded in knots and Beaufort and direction in 0-360° angle relative to true North and in
cardinal/ inter-cardinal directions (N, NNW, NW, etc.).
Auto-start after power off
If recording is interrupted due to power-off, no data is lost and after re-start log-entries resume at the end of previously recorded data. If at initial start-up the “autostart” feature is selected, the eLogger starts up without manual intervention after a power interruption, and continues with previously set parameters. This means that once started, the eLogger does not need any attention and quietly does its job.
Extra log-entries with stamp
Manual input to record certain events or circumstances is possible in the simplest possible way: By depressing any of the keys of the e-logger keypad, an extra log-entry is created, independent from the timed entries. The latest data is recorded as for timed log-entries, and in addition a “stamp” is included, consisting of the number or letter of the
depressed key. This provides a simple method of coding events. For example, 1 may be used for “change to starboard tack”, 2 for “change to port tack”, 3 for “land sighted” etc. Timed, non-stamped log-entries always have an X in the stamp-field by default.
Some stamped log-entries are made automatically:
1. First log-entry, immediately after e-Logger power-on (Stamp A)
2. When the engine is started (stamp E)
3. When the engine is stopped (stamp S)
4. When a DSC/DSE sequence is received from a DSC radio (stamp D)
Real time printing of log-entries
Direct real time printing of each log-entry on a compact, rugged mobile printer is available as an option. The automatic hard copy of each log entry provides independence from electronic media and guarantees that the latest information is available for
dead-reconing in the (unlikely) event that all electronics fail. The printed log-entries can be directly added to the hard-copy logbook or saved for later use.
After a passage, or at any other convenient time, the electronic log-book can be uploaded to a computer in several available formats. CSV (comma separated values) format can be used as input by programs such as speadsheet applications. Pre-formatted text is available as input for Word processing software and/or for printing other than directly on the rugged eLogger printer.
Instrument Repeater function
The eLogger's LCD also double-acts as a compact instrument repeater display. All GPS and instrument data, including the calculated ground wind speed and direction, can be displayed on the 32 position alpha numeric LCD. Data-displays can be selected by pressing the*-key on the keypad.
The “Waypoints” function, if selected at initial startup, automatically creates waypoints in an electronic chart at the same time log-entries are made. The waypoints are output from port 2 as standard NMEA
$GPWPL sentences. The vessel’s name, UTC date and time are used as the waypoint name. If port 2 is connected to the NMEA input of a chart plotter, a navigation program or to an iPad (via Brookhouse
iMux), the waypoints can be plotted real-time in the electronic chart. The track formed by the consecutive waypoints provides instant information about the progress of the vessel, and can also be used for navigation at a later point in time.
The plotted waypoints with date and time displayed can be used for a
variety of purposes. A single push of a keypad-key creates a
log-entry and a waypoint in the electronic chart. For example, fishing vessels may use this feature to mark locations where
lobster pots are set.
Waypoints with depth
If a keypad key is depressed while Depth is being displayed on the eLogger’s LCD, a waypoint is created with the time and depth as the waypoint ID. This is very useful for marking good anchoring spots or as supplementary depth information in the electronic chart. A separate “Depth Points” function is available for reconnaissance purposes, whereby the eLogger is used in a tender to find a safe navigable route for the main vessel.
See below under "Depth points".
An extra log-entry with stamp “D” is created when the eLogger receives a
DSC/DSE sequence from a DSC VHF radio. The DSC/DSE sequence is generated by the radio upon reception of a DSC Distress call, a DSC Position Send or Position Response after a Position Request has been sent. The position and MMSI of the other vessel are included in the log-entry and if the eLogger’s Waypoints function is active, a
$GPWPL sentence is output, with the date/time and MMSI of the other vessel as the waypoint ID. There are many applications for this feature. The waypoint can be used to navigate to the other vessel and the D-stamped log-entries provide a record of position and time of other vessels of interest.
Delayed waypoints creation
Instead of real-time, waypoints can also be created from the log-entries at a later stage. In this case, it is also possible to select log book entries with a certain stamp only. This allows selective plotting of waypoints of locations where certain events took place.
Creating waypoints from log-entries is very useful for reporting and trip documentation purposes.
This is not part of the main eLogger application, but a separate function, which can be selected at start-up. A record with date/time, position, depth and key is created each time a keypad key is depressed. In addition, an external push button can be provided to trigger creation of records. This simplicity of operation is ideal under difficult circumstances. Data is recorded separately from the
eLog. The purpose of this function is to create waypoints with the time and depth as the waypoint name, to be able to create a route for safe navigation through uncharted or inaccurately charted waters. The data logger can be used in the main vessel's tender for reconnaissance with only a GPS and depth sounder connected. The depth is displayed on the data logger's LCD, which allows the use of an active depth transducer without separate depth instrument. A GPS mouse and active depth transducer can be installed permanently in the tender, wired to a single connector that simply plugs directly into the data logger.
On the main vessel, wiring of the eLogger is also via a single
connector, which makes swapping quick and easy.
After return to the main vessel, the recorded data can be output as standard NMEA
$SDWPL sentences. By connecting the data logger port 2 output to a chart plotter or computer, waypoints with time and depth can be plotted in the electronic chart in a simple operation which only takes seconds.
The format is the same as depicted above under "Waypoints
with depth". Those waypoints that show sufficient depth can then be selected to create a route for safe navigation of the main vessel. The "stamp", i.e. the key that was depressed to create the waypoint is also displayed. This can be used to code certain observations, obstacles etc.
$SDWPL sentences are also output real-time, each time a data logger key is depressed.
By using an optional wireless link to a chart plotter/computer on the main vessel, depth information can instantly be made available to the navigator or skipper for safe navigation through reefs, channels etc. There are various ways of creating such a wireless link. For example, the following bluetooth product can be used: