Octo · Scuba Diving Theory

Open Water to Divemaster

Only for iPhone

Free

iPhone

Review scuba theory from Open Water to Divemaster in a few minutes a day: short lessons, quizzes that explain, spaced reviews and a practice exam for each level. Your next certification starts on dry land. Octo helps you review scuba theory from Open Water Diver to Divemaster, a few minutes a day, wherever you are. Unofficial app, not affiliated with or endorsed by PADI. Its lessons cover the topics of the PADI Open Water Diver, Advanced Open Water, Rescue Diver and Divemaster courses, written for the app from public course outlines and diving safety references. A FEW MINUTES A DAY • 62 short lessons: one key idea, a few cards and three takeaways. • Diagrams for pressure, air consumption, partial pressures and the dive profile. • Meters and bar, or feet and psi: your choice. • Every lesson you pass takes your depth gauge deeper. QUIZZES THAT TEACH • Six questions after each lesson, with the right answer and why. • Wrong answers based on mistakes divers really make. • Key safety questions come back more often. YOUR MISTAKES COME BACK AT THE RIGHT TIME • A missed question returns in today's review, then at longer and longer intervals. • Daily streak, daily goal, badges and a Home Screen widget. A PRACTICE EXAM FOR EACH LEVEL • 30 questions including real-life scenarios, scored at the end, optional timer. • Your progress attempt after attempt, and the module to review first. THE MEGA QUIZ FOR DIVE CLUB NIGHTS (OCTO PRO) • 300 questions from Open Water to Divemaster, plus marine life, dive sites and diving history. • 1 to 4 teams; 10, 20 or 30 questions; 30-second timer and sounds. • TV mode: questions and answers in large type on the club screen (AirPlay). FREE, OR PRO WITH A ONE-TIME PURCHASE Lessons, quizzes, reviews and practice exams are free, with a banner ad that never appears during a question. Octo Pro (one-time purchase, no subscription) adds the Mega Quiz and removes all ads. Octo doesn't replace your instructor or your training in the water. When in doubt, your instructor's word comes first. In English and French.

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The developer, Bruno Matthieu Pennes, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .

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Information

Seller
Bruno Matthieu Pennes
Size
11.3 MB
Category
Education
Compatibility
Requires iOS 26.0 or later.
  • iPhone
    Requires iOS 26.0 or later.
Languages
English and French
Age Rating
4+
Copyright
© 2026 Bruno Matthieu Pennes
  • Developer Website
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