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ICE ON ECDISPersonal views of Mike Eaton

( ex-mariner, involved in electronic charts since 1982)

These slides deal with ECDIS used for route monitoring in confined waters.

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Introduction Ice information is no use until the mariner can view it in the context

of all the info critical to safe navigation. This includes:

• - own ship (DGPS, radar)

• - safe water (minimal chart)

• - other ships ( AIS, ARPA)

• - other info (ice, currents, weather, VTS)

– – –

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Display design The display must be clear, uncluttered and

unambiguous in meaning: design from mariner’s view, for navigation safety design for worst conditions (sun on ice / dark night) max contrast between symbol and background code vital info by shape and colour prominence of symbol in proportion to importance standard conventional symbols for instant recognition minimum number of simple symbols colour coding to identify source of info keep software simple (speed draw and avoid crashes)

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Suggestions re new symbols on ECDIS

Follow general principles, particularly:

• as few new symbols as possible,• new symbols as simple as possible,• prominence proportional to overall importance to safety of

navigation.

Use established symbols, but consider different usage on ECDIS. Avoid duplicating existing ECDIS symbols.

Test symbology, on ECDIS simulator, and at sea if possible. Raw image overlays or cluttering patterns need ‘single action remove’

capability (as radar image). Minimise load on ECDIS processor ( to speed draw and reduce risk of

software crash). Coding similar to S-57 helps.

How it relates to your audience

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ECDIS in the future

Opinion: the bridge will need a single ‘Navigation Display’ showing all info. immediately critical to safe navigation:

• clear, unambiguous, uncluttered - a formidable requirement !

Approaches might include: Temporary detailed overlays: but mariners prefer not to

manipulate the display in critical situations. Distilled minimum of critical info shown all the time:

- needs formidable processing flexibility - a kindly user interface will be essential.

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Administrative status of ECDIS Evidently, ECDIS is just beginning. Many interests

need to be coordinated (and the least represented is the mariner). Here is the present status: IMO: ECDIS is no longer on the work list. Performance std.

covers chart; chartwork; radar; “other nav. info”. IHO: data & display specs ‘frozen’, with small thaws.

‘MIO’ WG on ice, currents etc. Dormant VTS proposal. IEC: performance test specs. plus chartwork, radar, AIS

symbols. ‘Frozen,’ with current small thaw.

Without IMO there is no overall coordinating body

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p.s. - Consider this ice symbology suggestion

For route planning, overlay an recognised ice plot, such as the WMO symbology.

For route monitoring, merge in a clear pattern of horizontal grey lines which causes minimal clutter (saved for ice), showing the ice situation as it applies to own ship. Uses three degrees of ice hazard:

• 1. no hazard to navigation,• 2. navigate with caution,• 3. no go.•

• For this to be feasible:

• need detailed ice info that is frequently updated,• need software to convert the data into above three

degrees of hazard.

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