The development of computer-based technologies has provided a fertile ground for the expansion of marine instrumentation. There have been many new products launched within the marine industry in the past few years, along with a number of new and very successful manufacturers and innovators. The result is that the previously well-established big players are now working a lot harder to keep their market share.
With all of this rapid progress, the smarter companies are utilising some of the lessons long since learnt in the computer industry, and some of the smaller companies are leading the way. There are a number of areas where marine instrumentation companies have leveraged these lessons, including such aspects as standardisation, user interface and systems integration.
Many years ago, the computer industry fought a standards war on a variety of different fronts, the outcome being that the industry learned that standardisation profits all, as it reduces costs and provides inter-connectivity between systems.
The standards body for all marine instruments is the National Marine Electronics Association (NMEA). This organisation is based in Maryland, USA, and provides a raft of standards for the design and implementation of marine instrumentation. The two standards of most interest are NMEA 0183 and NMEA 2000. NMEA 0183 is the older of the two and has been the subject of several revisions, the latest being version 3.01 dated January, 2002. The newer NMEA 2000 standard is designed to address the demands of some of the newer technologies.
Some manufacturers have their own protocol standards and, while this may provide some manufacturer-specific advantages, it means their instruments are usually not compatible with those from other manufacturers. However, many manufacturers make their instruments NMEA-compliant, as well as to their own standards. I would always recommend purchasing instruments that comply with the NMEA standards. Compliance means that instruments from different manufacturers, or of different generations should still be able to be connected together.
Some manufacturers have also adopted standards from the computer industry, such as Ethernet 100TX for fast data transfer and inter-connectivity. The adoption of this standard also facilitates the effortless integration of a computer into the instrument system, as we’ll discuss later. Auto-sensing on connection (referred to as plug and play in the computer industry) is also becoming more common.
The user console has become the focus of development in recent years. With the technological development of high-resolution, anti-glare, liquid crystal displays (LCD), the incorporation of these screens into marine instrumentation was an obvious development. The new user consoles are much larger and able to display a wide variety of information simultaneously. A few manufacturers have taken this thinking a step further and also incorporated touch screen technology. This makes the operation of the on-board systems more intuitive and also facilitates such common computer features as drag and drop.
One of the very latest developments in touch screen technology utilises invisible infra-red beams, making it unnecessary to actually touch the screen in order to operate it. The operator’s finger need only come into close proximity to the screen surface in order to activate the required function.
The user can integrate data from many sources and display it all on the one screen simultaneously. For example, instrumentation read-outs, such as wind data and vessel speed, navigation information, including electronic charts, GPS, radar, plus video input from different cameras around the vessel, access to onboard computers, internet browsing and DVD output can all be integrated into a single display.
From a navigation point of view, some exciting developments have been made possible with the integration of large volumes of data and the use of multi-input, large-format LCD screens. It is now common for these screens to overlay data from several sources onto the one image to provide a more complete picture. Some of these include:
The interconnection and complete integration of one or more computers directly into the instrumentation system is also a recent development. This provides many advantages, such as the ability to download weather charts (such as synoptic charts, wind maps or wave charts) from the internet and superimpose them onto the electronic chart to give more detailed information. Computers can also be used for improving navigation, monitoring of onboard systems and a host of other applications. Navigation programs can be run on the PC and the resultant data (waypoints, etc) uploaded directly to the chart plotter, while also storing the data on the PC’s hard disk for later re-use.
Autopilots have also profited significantly from the development of multi-input data streams. The integration of a rate gyro with a flux gate compass has provided an autopilot with superior behaviour characteristics resulting in performance similar to that of a human helmsman. The rate gyro measures and adjusts for the yaw of the vessel in a heavy seaway. This makes the vessel more comfortable for the occupants as well as reducing the wear and tear on the steering systems.
Integration of marine radios with the GPS and other instruments provides position and barometric data and time, all of which is very useful during an emergency.
The next, and perhaps the last area to be integrated into the operator’s console is engine management data. These systems provide a wide range of data on the operation of the engine(s) and fuel system. Some marine instrument manufacturers have formed commercial alliances with engine manufacturers to provide some very sophisticated engine instrumentation and management systems.
With the integration of systems, it is now possible to input data from one user console and then move to another console (eg: from the main helm station to the flybridge) and continue to operate the vessel whilst being able to view the same data. This feature can be very useful when operating the vessel in confined spaces or when entering an unfamiliar port.
The wireless environment is one of the newest technologies to find immediate application afloat. Wireless hand controls for the autopilot and engine controls allow the skipper to stand on the deck and bring the vessel alongside the pier; a useful feature especially when docking a vessel in a confined area or in trying weather conditions.
GPS technology has recently seen further improvements. There are now three new features being utilised in the more sophisticated GPS systems: Wide Area Augmentation System (WAAS); the European Geostationary Navigation Overlay Service (EGNOS) and Multifunction Transport Satellite (MTSAT).
WAAS covers America; EGNOS covers Europe, and MTSAT covers the Asia Pacific region. All provide increased positional accuracy and a much wider area of coverage compared to the existing land-based DGPS transmitters. There is also less interference due to weather and onboard electrical activity. The differential signals are sent on the same frequency as the standard GPS signal, thus negating the need for a separate receiver.
Unfortunately, the Australian government has decided not to participate in the development of MTSAT, meaning that Australia cannot enjoy the added accuracy and additional services furnished by this service. However, areas such as Darwin and Cape York are just within coverage zone.
Automated Identification System (AIS) is a system required by all vessels over 300 gross tonnes. However, AIS receivers are finding their way aboard small craft to warn of an approaching ship. AIS transceivers transmit data such as the boat’s unique ID number, position, course and speed to all vessels nearby as well as to the VTS stations. Principally, the system integrates a VHF transceiver to send and receive data and the GPS to provide the vessel’s data.
Man overboard alert systems are being integrated into vessel electronics, too. Each member of the crew wears a small personal transmitter that maintains a constant link to the vessel. Should the person fall overboard, the system detects the event and sounds an alert, also logging the GPS position on a monitor or chart plotter. The logged position is displayed with the track back to the person in the water.
Some forward-thinking manufacturers have incorporated the ability for the electronic system to self-diagnose problems, alert the user to the problem and provide some possible solutions. And a number of engine manufacturers have also incorporated internet links into their engine electronics to facilitate remote diagnosis.
The biggest enemy of all marine electronics is moisture, especially salt-laden moisture. While many manufacturers will describe their instruments as being waterproof – as in, resistant to penetration when immersed – very few instruments have the ability to resist moisture ingress when the temperature varies greatly over an extended period of time, such as those experienced on deck throughout the year in the temperate latitudes.
During the summer months, the atmosphere inside the instrument is heated by the blazing sun and thus it expands. This increases the atmospheric pressure inside the instrument and eventually forces out some of the enclosed gases. When the temperature drops during the winter months or while sailing in cold conditions, the temperature of the atmosphere inside the instrument drops. This causes a corresponding drop in pressure. After this has occurred a few times, the relative pressure inside the instrument is less than the outside ambient pressure. The resultant pressure differential causes a partial vacuum that draws in air from the surrounding atmosphere. The salt-laden moisture in the air can then corrosively damage the internal workings of the instrument.
It is difficult for manufacturers to build instruments that are completely resistant to these harsh conditions, although some instrument manufacturers claim that their instruments are completely sealed. The best solution is to only purchase quality instruments and try to keep the hot sun off them at all times.
It is imperative to calibrate new instruments once they have been fitted and are fully operational. Some instruments can be calibrated by reading the supplied documentation, while others will require a technician to do the job. Instruments such as speed logs and depth sounders can often be calibrated by carefully reading the manufacturer’s instruction manuals. The user instructions should give full details. If no instructions are supplied, call the manufacturer for advice. Instruments such as radar and autopilots require adjustment by a qualified technician.
While instruments can provide us with a wealth of information, they should be used with prudence. Many boaters have found themselves in serious danger because their instruments have completely failed or are giving erroneous data. Always use another means to confirm your position, instead of relying solely on the data provided by the electronics. Instruments are only as good as the levels of maintenance and calibration that you afford them.
It is always prudent to check and calibrate your instruments at every opportunity. Checking and calibrating should certainly be a part of your annual maintenance.
As technologies continue to evolve and become more complex, the inevitable outcome is that they will find their way onto more and more boats. How we adjust to them and use them to benefit our on-water time is largely up to us. But by becoming more familiar with them, we can certainly be better informed when we’re out on the water. And, ultimately, that has to result in a higher level of safety afloat.