The aim of this paper is to provide a collective overview of current state-of-the-art weather routeing and it is therefore intended to give a descriptive appraisal. Essentially the paper will concentrate upon the vessel route optimization procedures, data-handling techniques including the parameters necessary to implement the methods, the ship-resistance characteristics and the James speed performance curves.

In this paper a mathematical model is presented to explain the phenomenon of yawing oscillations of a ship, when sailing in a mean straight course with a constant mean speed. With this model, periodic yawing can be simulated as a result of simultaneous periodic rolling and pitching, emphatically without the input of any rudder action. Additionally, the study throws a new light on the old question of whether the Cardan suspension of the compass bowl should be with the outer gimbal axes fore and aft or athwartships.

The need for maritime navigation is obvious and the subject has a long history, indeed the science of navigation was mainly developed for maritime purposes. The areonautical requirement is nowhere near as old as the maritime, in the early days it was sufficient to follow roads or railways, the need for navigation came when crossing seas or not being able to see the ground for a large part of the journey. Space navigation requirements are even younger.

The Central Forecast Office Headquarters (CFO) in Bracknell has a number of national and international functions including a co-located World Area and Regional Area Forecast Centre in support of the International Civil Aviation Organization (ICAO). The CFO is also a Regional Meteorological Centre within the World Meteorological Organization (WMO) and a National Meteorological Centre for the United Kingdom. The CFO receives considerable support from an operational numerical prediction model. There are two versions of the model: a global version has a horizontal resolution of about 150 km and is used to produce forecasts up to 6 days ahead twice daily from 0500 GMT and 1200 GMT starting conditions with results available by 0500 GMT and 1700 GMT, respectively. A regional version of the model has a horizontal resolution double that of the global version and is limited to the area bounded by 80° W –40° E, 30° N – 80° N, with the lateral boundaries updated by interpolations from the global model. The regional model is used to compute forecasts up to 36 hours ahead twice daily, with results available by 0300 GMT and 1500 GMT. The fine-mesh model is used mainly to provide detailed forecasts of precipitation, cloud, surface winds and temperatures, which are better specified on relatively small horizontal grids. Physical and sub-grid scale processes are parametrized in the numerical model.

Potential points of collision (PPC) and predicted areas of danger (PAD) are used in marine radars for assessment of risk of collision and of action to avoid collision. Both are useful concepts for automatic radar plotting aids (ARPA) which lead to a better understanding of collision avoidance. The PAD display, developed by Sperry Ltd, is a graphic form3 alternative to the vector display. More information can be obtained from the PAD display than from the vector display but additional knowledge is necessary for the mariner to correctly interpret and use the information. The IMO Resolution on ARPA Performance Standards emphasizes the need for deck officers to understand the basic principles involved in the use of the equipment. In this paper consideration will be given to the information obtained from the PAD display and a suggestion will be made for possible improvement of the shape of the PAD.

Marine Safety Information is defined as the coordinated service of navigational and meteorological warnings, meteorological forecasts and distress alerts.

It represents the core information which the Master of a ship is required to receive under the provisions of chapters IV and V of the Safety of Life at Sea Convention (SOLAS).

In essence these cover the responsibilities of nations to broadcast messages relating to marine hazards, the obligation placed upon Masters to report such hazards, and to receive messages broadcast about them.

Three separate kinds of information are dealt with in the SOLAS Convention. First, Meteorological Services: these are the business of the World Meteorological Organization (WMO), which seeks to coordinate the work of various national meteorological administrations. Unfortunately a multitude of overlapping services and areas have grown up out of an expanding practical requirement and capability. This has resulted in overlap of services and consequent multiplication of effort.

The data base has become the heart of many of our businesses. This discussion will begin with an overview of the many aspects of how the data base is used and manipulated at Jeppesen Sanderson. The core of NavData has been named the Flight Information Master Data Base.

Marine radars, introduced generally for merchant ships immediately after World War 2, play a vital role in ship navigation and collision avoidance. They are now considered to be essential to a ship's safe operation and internationally agreed carriage rules and performance specifications exist for most classes of vessels.

Electro-optic sensors – forward-looking infra-red and night vision goggles – are today providing a dramatic enhancement of low-level operational capability, but causing increased demands for precision navigation, situation awareness and advanced displays. Digital map displays, also available today, offer the flexibility of map presentation that is needed. In the future, terrain-referenced systems incorporating digital data bases hold the promise of the integrated flying aid and mission displays that are required for ‘all-weather’ operations. This paper describes first the fit and usage of the EO systems likely in a future combat aircraft and goes on to review the status of data-base systems. It establishes the baseline against which digital map systems and later terrain-referenced displays that exploit an elevation data base might be integrated into the aircraft.