Preventing Marine Disasters - BOSAI: Science that Can Save Your Life

Key Concepts

• Rip Currents: Dangerous, fast-moving currents of water flowing away from the shore.
• AI Image Analysis: Using artificial intelligence to interpret and understand visual information from images or video.
• AR (Augmented Reality): Overlaying computer-generated images onto a user's view of the real world.
• Satellite Communication: Using satellites to transmit and receive data, enabling communication in remote areas.
• Bosai: Japanese term for disaster prevention and mitigation.

Digital Technology for Ocean Safety

This video explores how digital technology is being employed to enhance safety and prevent accidents in Japan's coastal areas, focusing on rip current detection and marine rescue systems.

Rip Current Detection System

1. The Danger of Rip Currents:

• Rip currents are identified as the greatest danger at beaches, capable of sweeping swimmers out to sea.
• They are formed by waves breaking and creating currents that flow both towards and away from the shore.
• Rip currents are difficult to detect with the naked eye, leading to accidents.
• Statistic: In 2024, 830 people were involved in ocean-related accidents in Japan, with 212 resulting in deaths or missing persons.
• Case Study: A tragic accident at Yuihama Beach in June 2025 saw two men swept out to sea, with one fatality.

2. AI-Based Detection Methodology:

• Problem: AI struggles to identify moving objects like water.
• Solution: Dr. Toshi Ishikawa developed a system using AI image analysis trained by experienced lifeguards.
• Training Data: Approximately 50,000 still images from videos of rip currents at Yuihama Beach were used to train the AI.
• Comparison: Still photos of the ocean without rip currents were also used for training.
• Performance: After six years of continuous learning, the AI achieved approximately 80% accuracy in detecting rip currents in real-time.

3. System Implementation and Features:

• Deployment: The system has been in use at Yuihama Beach since 2022.
• Infrastructure: Six cameras continuously record the coastline, sending 3-4 images per second to a university server for AI analysis.
• Alerts:
  • When a rip current is detected, a notification is sent to beachgoers' smartphones via an app.
  • Augmented Reality (AR) can display the rip current's location on the smartphone screen.
  • If someone is swept into a rip current, a rescue request is sent to lifeguards' smartwatches for rapid response.
• Accessibility: Anyone can use the AR function by scanning a QR code and downloading the app.
• Broader Applications: The system also displays hazardous areas like rocky coastlines and tsunami evacuation routes, addressing various marine risks.
• Nationwide Expansion: AI-based rip current detection systems are currently operational at six beaches across Japan.
• Drone Integration: In Fui Prefecture, the system is combined with drones that automatically fly to the location of individuals detected in rip currents, alerting them and facilitating swift rescues.

Marine Rescue System

1. The Need for Advanced Rescue Technology:

• Even with preventative measures, risks remain, necessitating technologies for life-saving in cases of being swept out to sea.

2. Yandaga's Location-Sharing App:

• Developer: Yandaga is developing an app to search for people in distress at sea, leveraging 25 years of scuba diving experience.
• Challenge: Standard diving computers with GPS can confirm location but lack a separate transmission function to notify others.
• Solution: The app allows users to share their location information even in remote areas like the sea, utilizing commonly used smart devices.
• Mechanism: If a person in distress cannot use a land-based internet connection, they can send their GPS-received location information to an internet server via a communication satellite.
• Rescuer Access: Rescuers can access this server to obtain the stranded person's location.
• Vital Signs: The system also shares vital signs data, enabling rescuers to assess the condition of a stranded person in advance.
• Medical Collaboration: Integration with medical teams allows for more precise rescue operations.
• Development Status: The satellite communication aspect of the system is still under development.

3. App Functionality Testing (Land-Based):

• Experiment: The app's functions were tested using a land-based internet connection with a smartphone and a smartwatch.
• Process: The two devices were connected via the app. The user's location was sent to the smartphone, displayed as an icon. The user then walked a distance to simulate being swept away.
• Result: After walking approximately 181 meters, the smartphone indicated the distance traveled.
• Benefit: Yandaga believes this system will enable people in distress to send their constantly changing location to rescuers, leading to faster rescue operations.
• Confirmation: Previous experiments have confirmed that location information can be shared even at sea.

4. Underwater Location Tracking:

• Research: Efforts are underway to locate divers underwater.
• Methodology: Underwater users send light signals from a device towards a camera installed on the water surface. The camera identifies the underwater user's ID and location.
• Findings: Researchers successfully determined a user's ID and location when optical signals were sent from a depth of 15 meters.
• Future Goal: Research aims to enable an app to identify a user's location whether they are on the surface or underwater.

Conclusion and Takeaways

Advancements in AI and communication technology are significantly improving disaster countermeasures for marine recreation. While enjoying the beauty of the ocean, it is crucial to remain mindful of its inherent risks and prepare accordingly. The integration of digital technologies like AI-powered rip current detection and satellite-based location sharing offers promising solutions for preventing accidents and enhancing rescue efforts in coastal environments.