Writing in 1623, Samuel Purchas declaimed, in Purchas his Pilgrimes, ‘The Sea yields the world to the world, by this art of arts Navigation’. In those days navigation and its handmaid hydrography were, indeed, each more of an art than a science, though the British had made great progress in the preceding 50 years towards making them scientific. I have taken as my thesis today that it was not until these two positionfinding ‘arts’ had become thoroughly scientific that there could be a science of oceanography. So I have called navigation and hydrography oceanography's eyes, for they enable the oceanographer to know where he is in the ocean and where phenomena occur in the ocean, both prerequisites to the observation, collection and organisation of positive knowledge about the seas and the oceans, which I take to be the basis of scientific oceanography.

The relationship between the scientist for whom the theory of tides has always offered a fertile field for academic research, and the practical man whose operational need for tide tables has seldom coincided with the desire to seek a full understanding of tidal phenomena, have played a fundamental role in the development of accurate tidal predictions.

Until the last decade, without the sympathetic collaboration of the scientist, the intelligent mariner was rarely able to satisfy the more demanding of his own requirements for tidal forecasts; academic dilettantism was (and still is) of little use to him. In the United Kingdom, the earliest recorded efforts, those of John Wallingford, Abbott of St Albans in the thirteenth century, were only intermittently improved, as for example by John Flamstead during the seventeenth century, until the full potential of Isaac Newton's work on gravitational theory was utilised systematically by Sir Joshua Lubbock, Lord Kelvin and Sir George Darwin in the second half of the nineteenth century. The extension and refinement of the framework of applied theory so formed was then taken over by A. T. Doodson until the dawn of the digital computation revolution just over a decade ago.

The nature, scope and quality of tidal predictions over the centuries have seen many changes in response to demands for improvement, which are as pressing today as at any time in the past. Perhaps the most remarkable feature of this trend has been the way in which the development of techniques for observing tidal variations—the raw material from which predictions are derived—has failed to keep pace with advances in theory, computational techniques and practical usage.

Records of water levels date from the first hydrospheric observations. The levels of inland and coastal waters are recorded with the use of tide gauges of various types and construction. The float-level gauge, however, is by far the most frequently used.

The oldest self-recording tide gauge was constructed by Henry R. Palmer, civil engineer of the London Dock Company, in 1831. A float resting on the water is placed in a well communicating with the river. The motion of the water surface is transmitted to the recording machine by wheels and shafts which act on a pencil rack. As the water level rises and falls, by the combined motions of a clock and the tide the pencil produces a line as a function of time.

Even today this principle is still used for float-level gauges. It represents the basis of the modern tide gauges for observing sea levels and their variations.

In 1831 we find another construction by Mitchell, which was erected in the Sheerness dockyard. A few years later Thomas G. Bunt developed a tide gauge, which was used on the eastern bank of the river Avon near Bristol from 1837 to 1872.

In 1834 the first self-recording gauge was erected in France, near Le Havre. On the other continents the first installations were established in Algiers (1834), in the United States and in India (1846), and in Australia (1858)

An installation in Hamburg (1861), which was developed by F. H. Reitz the engineer, is identified as the first German construction.

In 1870 fifteen tide gauges were known on the shores of the European continent (except the British Isles). By 1883 Carlos Ibañez was using information from approximately 67 tide gauge stations for the determination of the mean sea level around the European mainland. Today we find more than 300 installations in Europe, about three-quarters of which are working in north-western European waters and in the Baltic.

During the second half of the nineteenth century the United States of America embarked on a broad programme of scientific geographical exploration of the Arctic (Dodge 1961; Friis 1967). In the present century this programme has continued in cooperation with other nations, developing into a wide variety of co-ordinated scientific activities of considerable benefit to mankind and represents remarkable advances in hydrographic and oceanographic research. The very large role of the United States Navy in the history of these accomplishments is reflected in the seemingly limitless resource of extant records of the scientific work of its innumerable expeditions. It is perhaps timely that we review in brief the humble beginning and the motivations that combined to generate an interest by the Federal Government and the people in the exploration of the Arctic by the Navy Department.

In order to form an opinion on the prominent place of Dutch maritime cartography in the seventeenth and eighteenth centuries, comparison with the achievements of other European seafaring nations is required.

Sailing directions are one of the oldest aids to navigation that we know of in Europe [1]. Starting from the earliest, primitive descriptions of the courses (Octhere ca 800), the oldest sailing directions to Iceland/Greenland [2], and a brief description of the Bremen-Portulan fragment, from Jutland to the Holy Land (about 1200) [3], a long period covers the history of those descriptions of the courses, and information about routes for shipping in our latitudes.

The idea that only after 1490 the European sailors had ‘come for the first time in recorded history to struggle with the limitations placed on sailing ships by the winds and currents of the open ocean’ does not correspond to reality. There is enough proof to show that much earlier, in the fifteenth century, the North-East Trades’ regularity, the wind variability in the zone directly north of them, and the Canaries Current were already known. When the fifteenth century ended, the Portuguese had already verified the symmetry of wind patterns in the Atlantic on both sides of the equatorial calm zone, which led them to apply the significant name of ‘ventos gerais’ to the trade winds of both hemispheres.

Accurate knowledge of the wind and current systems was essential to good navigation and the Portuguese ratters of the sixteenth century, chiefly ‘carreira da India’ rutters, include an increasing amount of information on that subject, referring especially to zones in the passage from the North Atlantic to the South Atlantic. The report of a voyage (1503) proves that at that time the Portuguese already knew the Gulf of Guinea winds and currents sufficiently well. As a result of oceanic sailing, the traditional ratters, exclusively coastal, developed considerably, not only by adding data about latitudes and compass variations but also by the indication of winds and currents. There appeared also an even newer type of ratter, the ‘oceanic rutter‘, in which the safest and quickest routes, because of the changeability of winds and current patterns, are indicated.

Information about elements concerning winds and currents which are included in the Portuguese ratters was revealed in printed matter after the end of the sixteenth century and this allowed some European scientists to study, because of the availability of better information, the causes of those physical phenomena, which had already been treated briefly in the sixteenth century by two nautical treatise writers, D. João de Castro and Father Fernando Oliveira.

From the earliest times it was empirically known that a boat could be turned if the oar was put in the sea over the side of the boat. From the thirteenth century also it was empirically known that for this reason it is better to use a rudder over the stern. The reason for the boat turning was not known, although the question was put probably very early. In the seventeenth century such questions surely were posed in scientific treatises, but at that time it was impossible to find a satisfactory solution. Before the eighteenth century it was not possible to solve this problem of hydrodynamics (when the serious mathematical foundations of hydrodynamics were propounded in the works of Daniel Bernoulli, Pierre Bouguer, Leonhard Euler and other eminent scientists).

Those participating in this Congress are aware of the leadership of Rear-Admiral George Henry Richards in mounting the Challenger Expedition, which he himself regarded as the crowning achievement of his career. However, he also has a very special place in the history and development of British Columbia and it can fairly be said that his work in the Pacific Northwest was the major achievement of his sea-going career. His service on the coast covered the short period 1857 to 1863, but these were formative years in the development of the west coast colonies of Vancouver Island and British Columbia.

When the Challenger Expedition reached Sydney in 1874 this first European settlement in Eastern Australia was not yet a hundred years old.

Sydney was then a settlement of 140,000, among whom were several established scientists of distinction, as well as others who were to make their mark in future years.

The world's oceans continue to play a vital part in man's history on this planet. There is no doubt that in the long process of evolution man's early ancestors left the sea for the land. There is evidence too that some of these having progressed to the mammal stage returned to the sea to produce the dolphins, whales and seals. Some biologists believe that man's predecessors did likewise. Being driven by a shortage of food, they ventured into the shallow coastal waters to collect shell fish and other accessible sea food. During this period they lost much of their fur and learnt to swim. Unlike the aquatic mammals, they remained land animals. It must also be assumed that primitive man developed a great fear of the sea which remained with him even after he had developed the use of boats. Its storms, its vastness, its tides and its currents must have filled him with awe. Even in modern times seafaring occupations are considered hazardous pursuits and drowning as a cause of death is greatly dreaded. In the simple man's mind the dark ocean depths with unpredictable moods of violence create a sense of fear subconsciously supported by the fact that the newly born human being emerges from the dark and watery confines of the womb wherein it has, in its development, recapitulated the pattern of man's evolution. To return to explore the sea would be to retreat into the timeless past. It is not surprising, therefore, that extensive exploration of the sea and sea bed has lagged behind the extension of man's activity over the great land masses, the conquest of the highest mountains, the development of flight and in later years the conquest of space.

The authors have served in both Fishery Support Ships Orsino and Miranda, operated by the Board of Trade following the trawler losses in 1968.

They describe the history of the British Mission Ships first operated 90 years ago, as well as the origins of the Dutch and Portuguese services.

A detailed description is given of the events leading up to, and some experiences of, the present British service.

Finally, an account is presented of the services provided by some other maritime powers.

In 1850 the hand-propelled submarine boat Sea Diver, built by Wilhelm Bauer, dived out of control to the bottom when setting out to attack the Danish Fleet off Kiel. Shelford (1960) has described how Bauer and his crewmen Thomsen and Witt first tried to raise the boat using compressed air to blow the water out of the ballast tanks and, when the air was exhausted, they decided to try to escape by flooding the boat in the hope of equalising the pressure on the inside and the outside of the hatch. Eventually the hatch gave way and the first three underwater escapers arrived in a rush of air at the surface, to the surprise of those who had been grappling for the sunken boat.

It may be presumed that man began to dive almost as soon as he learned to swim, and to harvest corals, sponges and pearls from the seabed. These early divers employed the same breath-holding technique that is practised today by Indian and Arab pearl-divers, and by the diving Ama of Japan.

The relevance of fresh water in shipwreck survival conditions is shown with reference to the physiological effects of drinking sea water. The principles, construction and performance of solar distillation plants are discussed. The reliability and fresh-water costs from this method of desalination are put in perspective with those of conventional distillation processes. It is shown that installations with capacities up to 38 m3 (10 000 UK gallons/day) can be viable with other more complicated desalination processes.

This paper considers the evolution of the concept that the local distribution of animals in the sea is largely determined by the habitat preferences and behaviour of the animals themselves. Examples are mainly taken from studies on invertebrate animals. Nineteenth-century investigations on the behavioural responses of micro-organisms to such variables as light, salinity and oxygen, stimulated analogus investigations on the behaviour of marine invertebrates. From 1920 onwards, various lines of research have developed, notably on the settlement of marine larvae, but also on habitat selection by adult planktonic and benthic invertebrates, and on host finding by parasites and commensals.

Attention has been drawn to the relevance of genetic studies on behaviour, and to the significance of investigations on terrestrial animals. A synoptic view of habitat selection has been advanced in which animals respond to a complex of interacting stimuli from their physical, chemical and biological environment.

Simple models have been presented which consider the influence of dilution of the preferred habitat by less preferred alternatives, alteration of the rate of change of a habitat, the relation between habitat preferences and lethal limits, and the colonisation of new habitats.

The geological exploration of submarine canyons and valleys began late in the nineteenth century.Theories of canyon genesis are many, but the probable causes are turbidity currents or sediment slumps, or both. Recent biological investigations indicate that the faunal composition of canyons is quite different from adjacent depths without canyons. The predominance of motility in the fauna implies that canyons today are physically more dynamic than previously expected. Motility could be an adaptive strategy for survival in an unstable sedimentary environment, or the species may be trophic opportunists which are able to take advantage of the entrapment by canyons of large aggregates of organic detritus.

Intensive oceanographic research during the past 20 years has given new data on the distribution of the deep-sea bottom fauna, thus making possible the establishment of basic distribution laws. These new data on the composition and distribution of the deep-sea benthos have been used to study the relationship of both the whole bottom fauna and its separate groups to the peculiar environmental conditions of the abyssal ocean. In particular, recent work on polychaetes has shown the existence of a specific abyssal fauna among this most widely distributed oceanic group

In this paper the subject of faunal zonation in the ocean floor from the intertidal, and over the continental shelf, slope and rise and to the abyssal plain is examined on the basis of faunal change at the generic and species level. The region investigated over a period of five years aboard R/V Eastward is a Beaufort-Bermuda transect, approximately 75 kilometres wide and 500 kilometres long and bounded between 32° and 36°N latitude and 64° and 79°W longitude. A new method, involving numerical indices reflecting changes in the composition of taxa, endemism and diversity between adjacent depth levels, was developed for defining faunal boundaries. Isotherms and isobaths utilised by earlier authors for characterising deep-sea boundary on a global scale do not coincide with natural faunal boundaries. This study analyses the vertical distribution of 128 species of isopod crustaceans and 28 species of large epibenthic invertebrates. The zonation patterns seem to correspond with correlations in environmental conditions such as currents, topography and sediments.

We suggest four major vertical faunal provinces, characterised at the generic level, namely (1) the Intertidal Faunal Province; (2) the Shelf Faunal Province; (3) the Archibenthal Zone of Transition; and (4) the Abyssal Faunal Province and internal zones within these characterised at the species level. The main aspects of interest include the presence of a narrow ‘meso abyssal zone’ with a species maximum, the demonstration of the true transitional nature of the Archibenthal Zone in biotic and abiotic factors and the characteristic low-biomass Red Clay environment showing definite faunal isolation from the continental margin.

A diverse benthic and bathypelagic fauna was first incontrovertably established by the deep-sea samples of H.M.S. Challenger, and demonstrated the ability of organisms to live and reproduce in the deep, dark and cold abyssal environment of enormous hydrostatic pressure as high as 1000 atm (14 000 psi) on trench floors at 10 000 metres. The investigations of Regnard (1891), Fontaine (1930) and Ebbecke (1935) established that various shallow animals have the capacity to withstand increased hydrostatic pressure. This paper deals with the response of whole organisms, mainly shallow-water metazoans, to hydrostatic pressure-temperature effects. The level of occurrence of pressure-induced increased activity (R1), onset of paralysis or tetany (T) and LD50 are discussed for tropical and temperate marine species in relationship to temperature and hydrostatic pressure. The pressure sensitivity and resistance exhibited by different species are examined in relation to various hypotheses and theories such as (1) group effect, in which Schlieper (1968) claims that those shallow species that belong to the group which has successfully colonised the deep sea, such as Echinodermata, Mollusca, Isopoda, have a higher pressure resistance; (2) pressure resistance as a species or genetic property; (3) environmental impact, in which deeper species have a greater pressure resistance; and (4) finally a re-examination of temperature and pressure effects as these relate to deep-sea colonisation.