Sejlguide is a Danish app that focuses on the basic international maritime rules. It is designed as a quick reference for sailors, surfers, and other hobbyists in the Danish waters. The app contains references to sea marks/buoys, ship lights, steering rules, emergency signals, beacons, knots, bridge passage signals, and sound signals. Additionally, it includes a quiz to help sailors prepare for their proficiency certificate or speedboat license.

The content of the app is structured around the following categories: Sea marks / buoys - according to IALA region A; Identification signals - ship lights and signal figures; Steering rules - rules for steering and sailing; Emergency signals - the most common emergency signals; Beacons - markings on land and grounds; Passage signals - basic bridge passage signals; Sound signals - maneuver and warning signals; Knots and splices - Bowline and much more. Sejlguide is a free app that is perfect for anyone who wants to learn and stay updated on maritime rules and regulations.