One of the essentials of the Collision Regulations is that they should, so far as possible, eliminate doubt in the minds of navigators using them. In recent years, an amendment has introduced a serious, dangerous doubt.

I wrote a paper for this Journal called Fast Craft and Collision Regulations two years ago that was an attempt to highlight weaknesses in the current Colregs that had become apparent through the advent of large fast craft, mainly fast ferries. The paper offered possible amendments to the Colregs in order to correct the situation and bring some order to this increasingly complex situation. The matter of amendments to the Colregs was discussed at length right up to IMO sub-committee level, but amendment of the current Colregs was rejected largely because of the diversity of opinion about this subject. Without a consensus, it is difficult to effect change and with hindsight the proposals presented in my paper were too complex, and perhaps too far reaching. The purpose of this second paper is to propose a much simpler solution, one which takes into account current practice and which does not close the door to more defined action in the future.

The drift of sea ice ridges and hits on an offshore structure with dimensions 200 m by 200 m have been studied for the Dolginskoye oil field in the Pechora Sea. The calculations were made with the computer program ICEBERG. The mean drift speed of the ice ridges was found to be 0·21 m/s with a maximum speed of 0·89 m/s. The expected number of hits per year was calculated to be 737. It was assumed that a total number of 133000 sea ice ridges would be produced in (or have entered) the Pechora Sea per year. Under the same assumption, the expected number of ridges entering a safety zone around a platform of 1852 m by 1852 m was found to be 5649. However, due to uncertainties concerning the population of ridges, their shapes, sizes, drag coefficients and tidal action, the results should be used with care and only considered as indicative. The ridge drift pattern was predominantly to the northeast in the winter months. A structure located at Dolginskoye will most probably be exposed to sea ice ridges that are formed in the area around Khodovarihka.

The objective of this paper is to study the possible use of meteo-marine forecasts for correct management of ships' ballast water, in order to improve the safety of navigation, having due consideration to the economical costs (wrong load/unload of water) and the possible performance impacts that could be generated. The analysis has been carried out verifying the operative forecasts used for crew training in the Italian yacht Consorzio Prada for the America's Cup 2000 and issued in the period April–July 1999. Studying the forecasts' quality, situations of potential incorrect load of ballast water have been examined together with the potential negative effects. It has been demonstrated that an accurate weather forecast is of paramount importance to safe navigation without economic loss while recognising the related performance aspects.

At present, the whole shipping industry is concerned about safety of navigation. In particular, attention is focused on High Speed Craft. There has been a sharp increase in numbers of this kind of vessel, which primarily carries passengers but is also known to carry goods. Some units can reach speeds of over 45 knots with capacity for 900 passengers. These passengers have a basic right to life and their means of transport should obviously follow all safety codes, regulations and IMO resolutions. This paper describes the development of a monitoring system that could automatically transmit safety parameters and position from the ship to a management control centre. Digital and analogical alarms, ship condition readings and other safety-related parameters may be recorded and transmitted in near real- time using the latest communications and positioning technologies.

This paper develops a quantitative model for evaluating the difficulty of ship-handling caused by a restricted manoeuvring area or by traffic congestion or by a combination of both. It includes acceptance criteria based on the mariner's perception of safety. An attempt is made to evaluate the model by applying it to the specific environmental conditions of major ports in Japan. The model can provide information on the degree of ship-handling difficulty and so enable better design of infrastructure for waterways.

During the past thirty years, there has been a steady growth in the size and number of ships that use the Strait of Istanbul (Bosporus), which is one of the most difficult, crowded, and potentially dangerous waterways in the world. There have been over two hundred accidents over the past decade resulting in loss of life and serious damage to the environment. Many of the proposed export routes for forthcoming production from the Caspian sea region pass westwards through the Black Sea and the Bosporus en-route to the Mediterranean Sea and world markets. The risks and dangers associated with tanker navigation, maritime accidents and environmental catastrophe are aggravated with the increase in the density of traffic, tanker size and cargo capacity, as well as the nature of the cargo. In order to ease the problem, a Traffic Separation Scheme (TSS) was established and approved by IMO in 1994. This scheme has drastically reduced the number of collisions. However, one-way or two-way suspension of traffic in the Bosporus is inevitable for ships that cannot comply with the TSS because of their type, size or poor manoeuvring characteristics. The selection of size criteria to comply with the TSS has been a matter of discussion. This paper presents the results of a real-time simulation study investigating the manoeuvring performance of large tankers in the Bosporus. The study was conducted with a simulator capable of subjecting a given hull form to any combination of environmental conditions, i.e. wind, current and wave drift forces. The results indicate that, when realistic environmental conditions are taken into account, the size of ships that can navigate safely in compliance with the traffic separation lanes is limited.

This paper presents the application of GNSS1, or more precisely of Satellite Based Augmentation Systems (SBAS), to vertical separation for en-route, approach and landing operations. Potential improvements in terms of operational benefit and of safety are described for two main applications. First, vertical separation between en-route aircraft, which requires a system available across wide areas. SBAS (EGNOS, WAAS, and MSAS) are very well suited for this purpose before GNSS2 becomes available. And secondly, vertical separation from the ground during approach and landing, for which preliminary design principles of instrument approach procedures and safety issues are presented. Approach and landing phases are the subject of discussions within ICAO GNSS-P. En-route phases have been listed as GNSS-P future work and by RTCA for development of new equipments.

Digital Selective Calling (DSC) is causing serious problems for Search and Rescue (SAR) providers. Administrations must seriously consider the humanitarian and legal implications of continuing the implementation of DSC. They may be in violation of the Safety of Life at Sea Convention, the International Convention on Maritime Search and Rescue, 1979, and the United Nations Convention on the Law of the Sea, 1982, by knowingly implementing communications technology that may jeopardize lives at sea even though the primary intent of DSC is to establish a suitable distress alerting method. States may very well open themselves to legal liability if loss of life or environmental damage can be linked in any way to the known faults of DSC.

Anticipating that transport on the West European inland waterways will increase in volume, in ship size and in speed, experiments are being carried out to investigate whether safety of navigation – including traffic management – can be improved by the employment of GPS or DGPS, electronic navigation charts, river radar and computer technology. Although waypoint navigation and collision avoidance systems are generally accepted in the maritime world, these methods could cause problems when applied on inland waterways.

The content of this paper was presented at the International Maritime Association of the Mediterranean, 8th International Congress on Marine Technology in Istanbul, November 1997.

The effect of different measurement points on an acquired target is theoretically investigated with respect to the ARPA plotting performance. The target is described by simple geometrical figures and the echo is simplified. The actual measurement position is generally not at the centre of the target. This may cause errors in the standard plotting results. The characteristics of these errors are discussed from a nautical viewpoint.

My background is that of a professional navigator but, although I have spent a lifetime at sea, my experience as a harbour master gathering knowledge about problems in inshore waters has been limited to only the last three years. My aim is to be moderately – but deliberately – provocative in order to help stimulate discussion, though I suspect, with the strongly held views on the subject, this may not be necessary. I do not suppose there is anything new in what I am going to say and far greater minds than mine have been hard at work for many years in seeking solutions to some of the problems I will outline. Given all the diverse interests in this subject, there will perhaps never be a perfect answer but one of the important things is that the dialogue is ongoing, and embraces many organizations and authorities. This paper reflects the problems we perceive in the area of the Solent and, although some issues can be read across in general terms for other areas in the UK, the Solent is a unique area with perhaps unique problems. So what better place to start-Before I outline the scope of the problem, I must stress that the views I expound in this paper are my personal views, and should not in any way be considered official MOD policy. I would also like to say (and some readers may take issue with this by the end) that I believe my views are impartial – my main task as Queen's Harbour Master is to protect the interests of the Ministry of Defence and, once that duty is fulfilled, I have no commercial or financial axe to grind. When I look at some of the maritime safety problems, I can do so free from hindrance or pressure.

This paper, and the following two papers, were presented at a joint meeting sponsored by the Institute in association with the Honourable Company of Master Mariners and the London Branch of the Nautical Institute. The meeting was held at Trinity House on 20 November 1991. This first paper was read by Captain Houghton.

Over 20 years ago, collision with high ground was identified as being the single most significant cause of fatalities among air travellers worldwide (Smith, 1968), and some human factors responsible were highlighted. The three factors most commonly found to be present during major civil aviation accidents were: (i) pilot's visual flight in instrument meterological conditions (IMC); (ii) navigational error by the crew and'; (iii) pilot's failure to react correctly to new circumstances resulting from air traffic control (ATC) instructions or advice – sometimes made in a language foreign to that of the aircrew. The latter factor will be tested here to see if it still applies to recent cases in the UK.