MSC.530(106) requires Indications take in consideration the Accuracy of relevant hydrographic information

[alvarosanuy]

[alvarosanuy]

I believe the 'IHO interpretation' of this requirement should follow DQWG's guidance and limit the implementation to hydrographic features (anything with VALSOU) in depths=<30m. Point features for the time being (until S-100 is updates to support buffering of Curves & Surfaces).

NIWC has proven buffering of point features is currently possible but they highlighted buffering of Curves and Surfaces in PC would require changes to S-100.

This requirement has to work in addition to the requirement outlined in https://github.com/S-101-Portrayal-subWG/Working-Documents/issues/159.

S101PT must work with the ENCWG on a common approach to this IMO requirement.

[alvarosanuy]

Decisions made at Portrayal subWG meeting on 09/04/24

Leave issue open until MSC.530(106) implementation details are finalised (currently in discussions with the ENCWG).

[alvarosanuy]

Decision at PsWG meeting on 10/7/2024

Portrayal catalogue does not require amendments as no new Alerts (for CATZOC C, D, U) are required and there was no agreement to add additional portrayal to those features (e.g. translucent yellow colour on top of existing CATZOC symbology) as that would only create more screen clutter with no significant benefit to mariners.

• Any, On-Screen, ECDIS messages to alert mariners they would be entering or are navigating inside one of those Low Accuracy CATZOC areas will have to be implemented by OEMs.
• MSC.530(106) requirement on the use of accuracy information by mariners during route planning and/or monitoring will be also implemented by OEMs by enlarging the 'safety framework' defined by the user using the Horiz. and Vert. (worst case) accuracy values listed in the CATZOC table included in S-52 Ed 5.0.0 draft proposal (@Kusala9 - to be duplicated in S-98 Annex C ??). POSACC & SOUACC geometry/feature attributes won't be used due to the significant impact, real time, spatial evaluations would have on ECDIS' performance (as reported by OEM representatives).
• It was highlighted that the proposed 'accuracy evaluation' implementation of enlarging the 'safety framework' alone has shortfalls and would under-report cases when features, although not covered by the enlargement of those areas, would still technically be a potential danger if the Hor. accuracy was to be measured from the feature itself instead (Uncertainties in ECDIS - Shortfall.pptx). Mariners will be mislead and have a sense of safety that is not possible to guarantee by using the proposed method.

[alvarosanuy]

No changes to PC are required.