Although sailing is probably one of the oldest ways to travel in a sustainable way, the boats currently being build are far from sustainable. With wind, solar and tides often available one would assume this can easily be changed. It is great to see the growing attention boat builders and their customers give to sustainability.
The well known Ocean Race has published a roadmap to sustainable boat building: Sustainable Boat Building: Roadmap to 2030. Good to see progress is being made!