Essential Elements

In assessing modern AtoN system requirements three primary elements must be considered in terms of system functions, capabilities and the duration of the services provided by AtoN: functions, capabilities and durations.

Functions. Functions traditionally accorded to mariners by AtoN have been manifest as physical beacons and buoys whose functions based upon color, shape, topmarks and other characteristics have explicit meaning in the context of their use. Their placement within an overall AtoN system is used to denote tracks, routes, areas and limits implemented across the entire waterway using a systematic approach. Emulation of these same functions can be accomplished using Virtual AtoN to supplement physical AtoN. They may also be used when the deployment of physical AtoN or AIS AtoN is difficult or impossible. Virtual AtoN can provide additional capability to facilitate the electronic display of lines and symbols that represent areas, routes, tracks and limits directly on ECDIS or other system(s) by emulating the physical or AIS AtoN that are typically used to denote these functions or exhibiting new capabilities that are not possible with physical or AIS AtoN.

Capabilities. Capabilities for implementing AtoN functions have historically been viewed from a static point of view where, upon completion of a waterway design, physical AtoN are deployed to required locations. The ability to provide dynamic AtoN capabilities where their characteristics can change based upon a function of time and other factors has only recently been accomplished using AIS AtoN broadcasting area special messages. Virtual AtoN can be used to display in real time the detection of underwater hazards to navigation detected using 3D-FLS.

Duration. The use of physical beacons, marks, ranges and other apparatus including AIS AtoN continues to be the preferred method of deployment for channels, routes and other locations. Changes are made primarily resulting from experience and maintenance issues as they arise and not based upon new design and implementation methods.

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Virtual AtoN can also perform these same functions designed for use over long periods of time, the temporary marking of wrecks and other features as well as marking features with very short or momentary significance like a shipping container that is adrift, growler or whale directly in the vessel’s path.

5.1.3 Symbology

Traditional short range AtoN include marks in the form of beacons and buoys, ranges and other apparatus. A primary reference used in developing symbols representing these apparatuses is IHO Publication S-52, Specifications for Chart Content and Display aspects of ECDIS (IHO S-52). Within the United States NOAA (2013a) Chart No. 1 also provides guidance for ECDIS symbols.

A small sample of possible Virtual AtoN symbols similar to existing Cardinal, Lateral and Special Purpose marks in ENC and display on ECDIS are shown in figure 5.1:

V

V

V

V

_V

_V

V

V

V

V

V

V

V

North East South West

Lateral Marks

IALA A IALA B

Starboard Port Starboard Port

Special Purpose Marks

Starboard Port Emergency

Wreck Mark Isloated

Danger WaterSafe

Figure 5.1: Symbols for marks.

These Virtual AtoN symbols are alike to and differ from physical AtoN and AIS AtoN as shown in Figure 5.2 in the following manner:

1. The basic mark symbol is identical in all cases. This is an existing symbol that is in use and presently found in ENC and displayed on many ECDIS;

2. AIS AtoN utilize the basic mark symbol surrounded by a magenta circle denoting a radio AtoN. The letters “V-AIS” are also posted alongside the AIS AtoN mark to designate it as a virtual mark created by an AIS transmitter. This is an existing symbol that is in use and presently found in ENC and displayed on many ECDIS;

68 Cardinal Marks

V-AIS

V

(existing) Physical AtoN

(existing)

Figure 5.2: Comparison between physical AtoN, AIS AtoN and Virtual AtoN Symbols for marks.

3. Virtual AtoN utilize the basic mark symbol followed by the letter “V” posted alongside the mark to designate it as a Virtual AtoN. This is a proposed mark for Virtual AtoN that is experimental in nature and presently not in use. It is not found in ENC and presently cannot be displayed on ECDIS.

Not all ECDIS are presently equipped to display many of the symbols currently identified for use. Introduction of an extended symbol set into new ECDIS systems will begin in 2017 and continue after this date for older systems.

The capability of Virtual AtoN to emulate physical AtoN can also support new functionality that is not possible with physical AtoN. For example, some additional short range AtoN symbols that exist to represent tracks, areas and zones are illustrated in Figure 5.3.

Tracks and Routes Areas and Zones

B F No-Entry A C D E F Figure 5.3: Experimental Virtual AtoN symbols for tracks, areas and zones.

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These symbols may all be implemented as Virtual AtoN. Tracks A and B represent non-regulated, recommended tracks with two way vessel traffic not based on fixed marks. Route C represents a fairway designated by regulatory authority with minimum depth or maximum authorized draft. The width of the fairway, along with traffic separation zone D, is indicative of the span through which vessel traffic may safely pass. Area E represents an intuitive approach to designating a geographic area with irregular boundaries to supplement the present “–“, “┬“ and “< ” symbols found on ECDIS that require interpretation. Area F represents a geographic area whose boundaries expand a specified radius from the center, one implementation of which could be represented as shown using well understood “no-entry” symbols.

The tracks, routes, areas and zones illustrated here reflect only a small portion of symbols presently available, and soon to be available using ECDIS. There exists opportunities for further expansion of ECDIS symbols to include characteristics and capabilities that are not yet implemented, and possibly those not yet even conceived as the potential for Virtual AtoN technology becomes more fully realized.