JOSM Map Paint Styles (https://josm.openstreetmap.de/wiki/StylesSource):

• INT1_MapCSS.mapcss (rendering of nautical symbols according to IHO standard INT-1)
• CEVNI_MapCSS.mapcss (rendering of notice marks according to European standard CEVNI)
• BNIWR_MapCSS.mapcss (rendering of notice marks according to Brazilian BNIWR standard)
• PPWBC_MapCSS.mapcss (rendering of notice marks according to Brazilian/Paraguaian PPWBC standard)
• RIWR_MapCSS.mapcss (rendering of notice marks according to russian RIWR standard)

JOSM Tagging Presets (https://josm.openstreetmap.de/wiki/PresetsSource):

• INT-1-preset.xml
• Presets_Hafen.xml

JOSM Tagging Validator (https://josm.openstreetmap.de/wiki/RulesSource):

• Seamarks.validator.mapcss

To deploy these styles

• start JOSM
• Edit > Preferences > Map Settings > Map Paint Style
• Add a new style by entering URL
• eg. https://raw.githubusercontent.com/OpenNauticalChart/josm/master/INT1_MapCSS.mapcss

To deploy these presets

• start JOSM
• Edit > Preferences > Map Settings > Tagging Presets
• Add a new preset by entering URL
• eg. https://raw.githubusercontent.com/OpenNauticalChart/josm/master/INT-1-preset.xml

To deploy this validator

• start JOSM
• Edit > Preferences > Map Settings > Data Validator
• Add a new rule by entering URL
• eg. https://raw.githubusercontent.com/OpenNauticalChart/josm/master/Seamarks.validator.mapcss

Just make sure, the URL points to the RAW file content!