system, as well as evaluating the MarAd-developed selective calling equipment which uses middle-frequency, high-frequency, veryhigh-frequency, and L-band transmissions via satellite.

Mapping and Charting

Another factor that must be considered in the modernization of our maritime transportation system is the inadequacy of existing navigational and tidal current charts. Survey and chart construction criteria have been based on maximum vessel drafts of 45 feet. The emergence of the new crude oil carriers, with drafts approaching 100 feet and lengths of nearly a quarter of a mile, has changed the requirements for chart information. The sites thus far proposed for the location of offshore terminals are all in waters deep enough to permit ships with shallower drafts to traverse them easily and safely using existing charts. New deep-draft ships in these areas, however,

would often risk running aground unless they had extremely accurate charts of bottom depths and contours. Such exact and detailed charts do not exist. Erecting the terminals farther off shore in deeper water would solve this problem but, because construction and operating costs increase progressively with distance from shore and depth of water, this solution is economically unfeasible.

One of the objectives of the charting program of NOAA's National Ocean Survey is to provide special format navigation charts and tidal current charts for each terminal or superport before it becomes operational. Because of the importance of these installations and the danger of oil spills, detailed hydrographic and possibly wire-drag surveys of all proposed sites and the fairways leading to and from the terminal areas are being planned. As tidal currents are also critical to terminal and ship operations, extensive tide and current surveys will be made.

In the meantime, an attempt is being made to make the best use of presently available data and of survey efforts now in progress. Some 2,700 hydrographic charts, prepared in non-machine-readable form before 1965, are being digitized by the National Climatic Center. The National Ocean Survey is currently conducting hydrographic surveys in Prince William Sound, Cook Inlet, and Shelikof Strait, Alaska, and Puget Sound, Washington. These surveys were programed in anticipation of increased Alaskan maritime activity and mineral exploration.

NOAA nautical charts covering the Gulf of Mexico and other areas where the Bureau of Land Management is selling mineral leases have been overprinted, or are being compiled as the need arises, with designated navigational fairways and oil field blocks delineated by special symbols.

Other charting projects include coastal surveys and the preparation of charts for the use of coastal shipping and recreational boating interests. In this connection a total of eight National Ocean Survey vessels have been scheduled to conduct operations in U.S. coastal waters, and one will be employed in nautical surveys in the Great Lakes.

NOAA also supports an R&D program to improve the quality of its charts and to lower their production costs. One of these efforts has provided a method for expediting the production of charts of certain warmwater areas. Research in the use of colored aerial photographs for charting purposes has made it possible to rapidly and economically survey semitropical waters containing only a minimum of suspended sediment. Bathymetric mapping by photogrammatic means, however, is not at present suitable for use in most waters of the temperate zone.

Another project is directed to adapting orthophoto techniques and random dot printing to the production of, harbor charts.

Orthophotography removes the normal distortions in aerial photographs caused by the tilt of aerial cameras and varying ground elevations. The result is a precise photograph in which the horizontal positioning of surface features is correctly depicted. The random dot printing of negatives retains important details that are commonly lost in other methods of reproduction.

Harbor charts incorporating these 'echniques will combine standard hydrographic information such as water depth contours and bottom characteristics, with random dot printing of orthophotographs of the adjacent land areas. Prototype charts of this type have been well received, and a chart of Fort Pierce Harbor, Florida, has been issued. Similar charts of four other Florida harbors are now in the planning stage.

Deepwater Ports

No existing U.S. harbor receiving crude petroleum has either the facilities or the natural depths to handle supertankers ranging upward to 540,000 dwt and drawing as much as 94 feet of water. Moreover, problems resulting from this inadequacy to handle large ships are becoming more severe because the increase in vessel size being experienced in the shipment of crude petroleum is now beginning to develop, although to a lesser extent, in the shipment of

dry bulk commodities. The existing depths of channels serving the dry bulk carriers are generally inadequate to accommodate the larger vessels being employed in these trades.

As noted in chapter III of last year's Federal Ocean Program report, Congress, recognizing the growing inadequacy of the U.S. ports, authorized the U.S. Army Corps of Engineers to conduct regional deepwater port studies on the North Atlantic, Gulf, and the Pacific coasts. Interim reports resulting from these studies have now been completed. While the reports made no recommendation for Federal participation in the development of deepwater port facilities, they have reached some general conclusions. First, deepwater port facilities can be justified only by a present or near future need to import foreign crude petroleum. Such a need exists, and there is economic justification for one or more deepwater port facilities on the North Atlantic, Gulf, and Pacific coasts to serve superships transporting crude petroleum. Several likely alternative systems and potential site and facility combinations were identified on each