Brazil's First S-101 ENC: What Survey Contractors Should Plan For

What Happened

The Brazilian Navy’s hydrographic office, the Centro de Hidrografia da Marinha (CHM), validated its first Electronic Navigational Chart in the S-101 format: the Port of Suape cell in Pernambuco. The cell was validated against the S-101 ENC Product Specification, Edition 2.0.0.

CHM ran the work as a structured project, through initiation, planning, execution, monitoring and control, and closure, in a controlled database environment kept separate from routine ENC production. That separation is the notable engineering decision: it let the office develop the S-101 workflow without disturbing ongoing production of S-57 ENCs and paper and raster charts for the same area.

Validation used an ECDIS and an S-100 viewer for cross-checking, plus compliance checks against the official verification packages provided by the IHO and the Regional ENC Coordinating Centre (RENC). From 2026, CHM plans to expand S-101 production to other strategic areas along the Brazilian coast, gradually, as its technical teams build expertise. CHM has also committed to producing future S-101 charts alongside new editions of the other products covering the same area, including S-57 ENCs.

That last point matters more than the milestone itself: Brazil is now entering a dual-fuel period in which S-57 and S-101 deliverables coexist.

Why This Matters

S-101 is the next-generation ENC product specification under the IHO’s S-100 Universal Hydrographic Data Model. It replaces S-57. Phase 1 of the S-100 framework entered into force in January 2026, and S-100 ECDIS became legal for use from 1 January 2026. The mandated dual-fuel period, in which S-57 and S-101 ENCs are carried in parallel, runs to 1 January 2029, after which new IMO ECDIS Performance Standards take effect. In practice S-57 carriage will persist well beyond that as the installed ECDIS base turns over. CHM validated the Suape cell ahead of entry-into-force, the kind of pre-mandate development work a national hydrographic office does to be ready before the framework binds.

So the correct reading of the Suape cell is a planning signal, not a switch being thrown. The link to survey work runs through charting: hydrographic survey data feeds ENC compilation and updates, so contractors supplying survey deliverables to CHM, or to commercial charting producers, for route planning, pipeline corridors and installation-site assessment in Brazilian waters will increasingly be asked to deliver in a form that flows into S-101 ENC production. That does not make every survey deliverable an S-101 cell; it means contractors who produce ENC-grade product, or feed those who do, are the ones who need S-101 capability. The timeline is a multi-year dual-fuel transition driven by CHM’s gradual rollout from 2026, not an immediate contractual requirement.

What does change concretely is the data model. S-101 uses a feature-catalogue model with stricter attribution rules and expanded, often mandatory, metadata. It is designed to interoperate with other S-100 products such as bathymetric surfaces (S-102) and water level information (S-104). This is a change in data architecture, not a file-format swap, and it touches acquisition planning, processing and quality assurance.

The Practical Reality

The CHM experience is the most useful evidence available, and it is sobering. Even a national hydrographic office with deep charting experience could not simply auto-convert S-57 to S-101; the work involved deliberate alignment of features and attributes and adjustment of portrayal, inside a controlled database. A survey contractor coming to S-101 cold should assume the same kind of effort, not a one-click export.

The recurring misconception is that S-101 is “S-57 with better metadata.” It is not. The feature encoding is different. A workflow built on S-57 assumptions tends to fail in predictable ways: processing software that does not handle S-101 feature attributes, QC tools that cannot validate S-101 portrayal rules, and client ECDIS that cannot display the result. Each of those surfaces late, as rework rather than as a caught error.

Brazil’s mitigation, a separate production database, parallel S-57 production and phased validation, is a reasonable model for managing two formats through a transition. It is the part of the Suape story most worth copying.

Where the Risk Sits

Treating S-101 as a software upgrade

The most common error is reading “S-101 output” in a scope and budgeting for a software update. S-101 changes how features are encoded, so it is a workflow change, not just a licence change. The table below is illustrative of the type of change rather than a verified mapping from any single source; confirm specific feature-class names and attributes against the S-57 Object Catalogue and the S-101 Feature Catalogue (Edition 2.0.0) before relying on them.

Aspect	S-57 (Edition 3.1)	S-101 (Edition 2.0.0)
Object model	Six-letter object acronyms (e.g. OSPARE for an offshore production area)	Named feature classes with a richer feature catalogue
Attribution	Mandatory and optional attributes per object	Stricter attribution rules and more mandatory metadata
Updates	ENC update cell	S-100 maintenance/update mechanism

A further complication: portrayal is catalogue-driven and ECDIS implementations differ, so the same compliant dataset can display differently across systems. That is a reason to confirm output against the client’s actual fleet ECDIS rather than assume specification compliance guarantees a consistent picture.

Underweighting metadata and uncertainty

S-101 makes mandatory several attributes that were optional in S-57, including survey date and position and depth uncertainty. These feed safety-contour and under-keel-clearance behaviour in ECDIS, so they are not bookkeeping. Uncertainty has to be carried through honestly from its sources, GNSS, motion, sound-velocity and multibeam depth uncertainty, in line with the relevant order of IHO S-44 Edition 6.1.0 and its bathymetric-coverage terminology, and then represented in the feature attribution. This is the discipline most acquisition-to-product chains have not yet wired together.

Underestimating QC change

S-57 QC is mature and largely about format, visual check and source comparison. S-101 QC additionally has to test feature-catalogue compliance, portrayal rules and interoperability with other S-100 products. CHM validated desktop-side with an ECDIS and an S-100 viewer; reproducing equivalent checks inside an offshore production workflow is harder. Expect QC effort to rise during the first projects before settling, and do not over-trust automated validators: they catch specification violations but can miss logical errors, such as a wreck component with an incorrect vertical-datum attribute that passes validation yet yields wrong clearance.

Overlooking dual-format deliverables

Because Brazil is in a dual-fuel period, single surveys may need to be delivered in both S-57 and S-101. There is no clean one-to-one mapping between the two: elements exist in one and not the other, some attributes do not transfer, and portrayal differs. Maintaining two formats means a change in one has to be reflected in the other, metadata included. That is a change-management problem more than a technical one, and it is where teams without a defined process lose time.

What Actually Helps

These are the capabilities a survey manager should demand evidence of, framed so they drop straight into a scope of work rather than staying supplier-side advice.

Require evidence of a capability check rather than a vendor claim. In the scope, ask the contractor to confirm that its ENC production software supports S-101 Edition 2.0.0 and to demonstrate that the subsea features that matter, cables, pipelines, wellheads, manifolds, structures, are covered; vendor “support” alone does not guarantee it. Require a documented, version-controlled mapping of each survey feature to its S-101 encoding, kept current as the specification evolves.

Require evidence of training before fieldwork. The S-101 feature catalogue, mandatory attributes and QC procedures are enough material for a dedicated workshop, and the scope should require at least one team member with genuine S-101 encoding expertise, which matters most where connectivity is poor and decisions have to be made on the vessel. A useful low-cost step the contractor can be asked to evidence is an internal pilot: take archived survey data, produce both S-57 and S-101 from it, run the S-101 cell against the specification and against more than one ECDIS, and record where it breaks. That surfaces workflow gaps before a client contract does.

A liftable acceptance test for any bidder’s S-101 claim: require a sample S-101 cell produced from supplied archived survey data, rendered correctly on at least two named ECDIS systems, accompanied by a passing IHO/RENC verification-package report and a documented feature-to-S-101 attribute mapping. A bidder that cannot produce all four under controlled conditions does not yet have demonstrated S-101 capability.

Build a realistic time buffer for early S-101 projects rather than assuming parity with the S-57 cycle. The honest position is that the first projects will take materially longer and that the overhead falls with experience; size the buffer from your own pilot rather than from a published figure.

What to Expect in Tenders

Over the dual-fuel transition, operators in Brazilian waters will start to ask for S-101 capability in tenders, first as a desirable, then as a discriminator. Expect requests for demonstrated S-101 production capability (software, trained personnel, QC procedures), example deliverables or test datasets, workflow documentation, and a statement of compatibility with the client’s ECDIS fleet. Some clients will issue data dictionaries specifying how particular features and their attributes should be encoded, including acceptable uncertainty.

This matters because S-101 allows complex features, an offshore platform with accommodation, helideck and mooring, to be encoded as one composite feature or broken into parts. Clients will have preferences, and confirming them before encoding avoids rework. Expect, too, that some clients will want S-101 for archiving and regulatory purposes while their fleets still run S-57 day to day, so contracts should cover both formats explicitly.

The Wider S-100 Picture

S-101 sits inside the S-100 framework alongside the other Phase 1 specifications, including bathymetric surfaces (S-102), water level information (S-104) and surface currents (S-111). The intended payoff of S-100 is interoperability: these datasets are designed to work together in S-100 ECDIS rather than as isolated files. The data-management disciplines this demands, version control, change tracking and archiving, are standard for any critical dataset and are exactly the disciplines a dual-format deliverable obligation forces a contractor to formalise.

Bottom Line

Brazil’s first S-101 ENC at Suape is a credible, well-documented start to a national transition, not a deadline. The realistic posture for survey contractors in Brazilian waters is to build S-101 capability deliberately during the dual-fuel period, prove it on archived data, and confirm client encoding and ECDIS requirements in the tender phase. The advantage goes to teams that treat S-101 as a workflow and QC change and start practising before a contract requires it.

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Based on: Brazil Achieves a Milestone in Digital Nautical Cartography with the Production of its First S-101 ENC