A lightweight, autonomous and portable solution for marine data
Introduction
While PostGIS is ideal for structured, collaborative and multi-project professional environments, it is not always necessary — nor desirable — for all use cases.
For:
- one-off or exploratory studies,
- embedded or mobile projects,
- data exchange between organizations,
- or offline usage,
the GeoPackage (GPKG) format represents a simple, robust and standardized alternative.
In this article, we explore the GeoPackage mode of S57Manager, designed to offer the same level of structuring, control and data exploitation as the PostGIS mode, without any server dependency.
👉 The plugin automates the processing chain described in the following articles:
- ENC charts in GeoPackage with QGIS – Final version: Part 1
- ENC charts in GeoPackage with QGIS – Final version: Part 2
1. Why choose GeoPackage?
GeoPackage is a widely adopted OGC standard in the GIS ecosystem.
Its key advantages include:
- single-file storage,
- OGC standard format,
- portability (USB drive, external disk, cloud),
- versioning capabilities,
- compatibility with QGIS, ArcGIS and GDAL/OGR.
👉 It is particularly suitable for:
- engineering consultancies,
- field or onboard missions,
- inter-agency data sharing,
- low-connectivity or offline contexts.
👉 In S57Manager, GeoPackage is not a degraded mode:
it follows the same structural principles as PostGIS, adapted to file-based storage.
2. Configuring GeoPackage mode
2.1 Creating or selecting a GeoPackage
The user defines the working directory used for GeoPackages.
The plugin uses four GPKG files:
enc.gpkg
→ main file containing the final result
(up to ~260 S-57 tables)- three temporary import GeoPackages:
pointsENC.gpkglinesENC.gpkgpolysENC.gpkg
These files are used as intermediate steps during the import process.
Plugin behavior:
- GeoPackages are automatically created if they do not exist;
- existing files are reused;
- the
enc.gpkgfile is progressively enriched with each import.
👉 As with PostGIS mode, the internal structure is fully managed by S57Manager, ensuring consistency and reproducibility.
2.2 Layer organization
Data organization follows the same principles as in PostGIS:
- one table per S-57 object class,
- clear separation between point, line and polygon geometries,
- consistent naming and attributes across both modes.
This consistency enables:
- smooth migration between GeoPackage and PostGIS,
- easier interpretation by third parties,
- reuse of styles and workflows.
👉 A QGIS project built on GeoPackage can later be migrated to PostGIS without changing layer logic.
3. ENC → GeoPackage import
ENC import into GeoPackage relies on the same processing chain as PostGIS mode:
- decoding via GDAL / OGR,
- logical interpretation of S-57 objects,
- geometry-based separation,
- creation of normalized final tables.
The difference lies only in the storage backend.
The plugin guarantees:
- identical logging,
- the same validation checks,
- no functional loss compared to PostGIS.
👉 Choosing GeoPackage is therefore an architectural choice, not a compromise on data quality.
4. Data control and consistency in GeoPackage
Even with file-based storage, ENC data remains:
- standardized,
- semantically rich,
- critical from a navigational perspective.
The data checks described in the PostGIS article therefore remain fully applicable:
- presence of expected layers,
- geometry validity,
- consistency of coded attributes,
- overall nautical logic.
👉 QGIS allows most of these checks directly on GeoPackage through:
- geometry validation tools,
- expressions and filters,
- internal SQL queries.
5. Working with ENC layers locally in QGIS
Working in QGIS is identical to the PostGIS workflow:
- display by ENC object families,
- filtering by purpose,
- scale-dependent rendering,
- nautical-oriented styles.
Performance is generally very good for:
- limited spatial extents,
- single-user workflows,
- embedded projects.
👉 GeoPackage enables clear, progressive and coherent cartography, without requiring server infrastructure.
6. PostGIS / GeoPackage comparison
| Criterion | PostGIS | GeoPackage |
|---|---|---|
| Multi-user | ✅ | ❌ |
| Large datasets | ✅ | ⚠️ |
| Portability | ❌ | ✅ |
| Simplicity | ⚠️ | ✅ |
| Deployment | Server | File |
| Offline use | ❌ | ✅ |
| Embedded projects | ❌ | ✅ |
👉 The two approaches do not compete — they complement each other.
Conclusion
The GeoPackage mode of S57Manager makes ENC data accessible without heavy infrastructure, while preserving:
- ENC semantic richness,
- rigorous data structuring,
- consistent exploitation in QGIS.
It naturally complements the PostGIS approach, making S57Manager a versatile tool adaptable to:
- institutional environments,
- lightweight, mobile or exploratory use cases.
