Maritime Buoyage on 3D-Printed Tactile Maps
Mathieu Simonnet, Serge Morvan, Dominique Marques, Olivier Ducruix, Arnaud Grancher, Sylvie Kerouedan · 2018 · Proceedings of the 20th International ACM SIGACCESS Conference on Computers and Accessibility (ASSETS '18) · doi:10.1145/3234695.3241007
Summary
This demonstration paper presents work from the Brest Bay Touch project to create 3D-printed maritime maps accessible to people with visual impairments, with a particular focus on representing sea marks (buoys, lighthouses, and other navigational aids) as tactile symbols. The maritime environment offers unique opportunities for blind and visually impaired people — many actively sail — yet virtually no tactile charts exist for maritime navigation. The researchers used a co-conception (co-design) process involving two blind sailors with extensive sailing experience, computer scientists, an ergonomist, and a cartographer. Together they developed distinct 3D-printed shapes for 11 types of maritime buoys, following International Hydrographic Organization standards as closely as possible while adapting for tactile perception. The shapes include cones with spheres for lighthouses, extruded triangles for lateral buoys, vertically aligned triangle pairs for cardinal buoys, crosses for special marks, and half circles for mooring buoys. The team used 3DSmax for modeling, Cura software for slicing, and an Ultimaker 2+ printer. A key technical challenge was determining the minimum size at which each buoy shape could be reliably identified by touch.
Key findings
Initial co-conception feedback established that buoy symbols needed to be at least 5mm in size to be quickly recognizable by touch while minimizing cognitive load during map exploration. The researchers designed an experimental protocol inspired by the Monoyer scale used in optometry, where participants identify lines of shapes decreasing in size from 7mm to 3mm. Previous research indicated that 3mm gaps between elements are needed for tactile discrimination, but minimum perceptible size depends on shape complexity. A 1:20,000 scale was chosen for coastal approach areas, where 200m between sea marks translates to 10mm on the map — sufficient space for 5mm buoys with adequate gaps. The 3D-printing approach offers several advantages over traditional tactile maps: lower cost, ability to represent real 3D physical shapes rather than flat raised symbols, customizable areas and scales, and modular tile assembly (18cm x 18cm tiles representing approximately 3.6km each) that can be combined like puzzle pieces for larger coverage.
Relevance
This work demonstrates how 3D printing is expanding accessible cartography beyond the flat raised-line maps that have traditionally been the only option for people with visual impairments. The maritime context is particularly compelling because it serves an active community of blind sailors who need spatial understanding of coastal environments for safety and independence. The co-design methodology — iterating between discussions and hands-on testing with blind users — exemplifies best practice in accessible technology development. The Monoyer-inspired sizing protocol offers a replicable method for determining minimum tactile symbol sizes in other 3D-printed accessibility applications. While this is a short demonstration paper presenting preliminary work, it points toward a future where personalized, on-demand tactile maps can be produced affordably using consumer 3D printers and geographic data, potentially transforming access to spatial information for people with visual impairments.
Tags: 3D printing · tactile maps · visual impairment · spatial cognition · maritime accessibility · co-design · blindness
Standards referenced: International Hydrographic Organization (IHO) Standards