CSI is a citizen science project that bridges the 'data gap' in coral reef research and conservation. We mobilize recreational sailors—our 'vessels of opportunity'—to monitor coral reefs in remote locations. By collecting standardized video data, we help scientists track reef health, bleaching events, and biodiversity in isolated regions that are otherwise too expensive to monitor regularly.

Scientific expeditions to remote atolls are logistically difficult and expensive. Cruising sailors, however, are already there. We anchor in the precise locations where data is most scarce. Our mobility allows us to build a global, decentralized monitoring network with a significantly lower carbon footprint than dedicated research vessels.

Not at all. The protocol is designed specifically for non-scientists. If you are a competent swimmer or freediver capable of maintaining a steady pace and operating an action camera, you can contribute. No taxonomic training is required.

• Imaging Device: A waterproof action camera with image stabilisation capable of 4K recording (e.g., GoPro Hero10 or newer). A handle or selfie stick is helpful.
  Other camera options +

  Olympus Tough or other underwater cameras?

  Underwater Photo Cameras usually lack good image stabilisation and videos can only be recorded in HD. Still, we can stabilise even quite wobbly videos and especially in remote areas even HD instead of 4K videos can be very valuable. So, if you don't have the latest action camera but still want to contribute videos, please This email address is being protected from spambots. You need JavaScript enabled to view it. - we'll figure it out.

• Geolocation: A GPS unit to record a continuous track.
  Compare GPS Options +

  Old Android Phone

  Pro: Free (reused) Pro: Easy export Con: Battery life

  Needs a waterproof pouch.

  Recommended App: GPS Logger download link

  • In settings, choose a "Local Exportation Folder" to tell the app where to save the track file.
  • Set "GPS Update Interval" to 2s. This decreases the file size and is accurate enough.
  • Choose "Export tracks in GPX".
  • After recording, export from the tracklist, share or send by email.

  Price: $0

  Garmin eTrex SE

  Pro: Rugged/Waterproof Pro: AA Batteries Neutral: Basic Screen

  Dedicated outdoor tool. Reliable but data transfer requires cable or app pairing.

  Price: ~$150

  Columbus P-10 Pro

  Pro: Professional Accuracy Con: Specialized/Expensive

  Sub-meter accuracy for serious mapping. No navigation screen (pure logger).

  Price: ~$300
• Accessories: A swim buoy/drybag combination or simple drybag with tether for the GPS unit. The GPS needs to be above water at all times

Yes, these settings are required for data validity:

• Resolution: 4K at 30fps is standard (2.7K minimum).
• Lens Mode: Please use the "Linear" zoom setting.
• Why? Wide-angle or fisheye views distort the image, making it hard to calculate the surface area of the reef later.
• Time: Make sure time and date are synchronized with GPS unit.

The survey is a timed swim approximating a 20-meter line:

• 1. Preparation: Sync camera & GPS time. Put GPS in waterproof bag and attach tether. Start GPS tracking before entering the water. Record the track of your complete in-water-session.
• 2. The Approach: Swim to your first start point for at least 10 meters at a 90° angle.
• 3. Recording Sequence:
  • 00:00 (Surface): Record horizon/landmarks for context.
  • 00:02 (Subsurface): Dip camera and record a slow 360° reef panorama.
  • 00:30 (Metadata): Show hand signals for depth (e.g., 3 fingers = 3m).
  • 00:35 (The Swim): If the depth exceeds 2 meters, dive to about 1.5m above the bottom. Swim straight for ~60 seconds (approx 20m). Keep camera 1m from bottom, facing down and slightly forward.
  • 01:35 - 02:05 (Finish): Ascend and record a final slow 360° view.
• 4. Egress: Swim away from the end point at a 90° angle for at least 10 meters to mark the GPS track.
• Note: we are now doing the 360° reef panoramas slower than shown in this video.
• Repeat as many times as you like.
  Each clip / transect recording should be approximately 02:05 min long, plus-minus 10 seconds or so. During your snorkel session you can do as many transects at as many different spots as you like but make sure to approach and leave each new stretch at a right angle. If you don't want to dive down, you can still record sites to about 2 meters deep. At high tide you can also record the shallow reef flat, keeping the camera just below the water surface – tilt the camera forward more, so the distance between reef and center of image is about 1m.

Absolutely, yes! However, be aware that this is more challenging than snorkeling and is recommended for advanced SCUBA divers only.

• Context: Instead of the view above water at the start, simply film your dive computer to record depth and water temperature.
• GPS Logistics: Your buddy takes the surface GPS buoy. They must ensure they approach the starting point and leave the end point perpendicular (at a 90° angle).
• Precision: Your buddy needs to keep the tether as vertical as possible and follow your path as exactly as possible to ensure the GPS track precisely matches your video location.

Safety first! Never compromise your dive safety for data collection.

We ask you to swim towards your start point and away from your end point at a 90° (perpendicular) angle. This geometric turn creates a clear 'corner' on your GPS track, allowing our software to pinpoint exactly where the scientific transect begins and ends without manual guessing.

The left panel of this image displays the raw, continuous GPX track of an entire in-water session. The right panel illustrates the segmentation process, where individual transects (highlighted in yellow) are delineated from the continuous track by using the distinct 90° turns during the Approach and Egress phases.

Please be careful not to touch any coral during the whole process. Make sure that none of your anchor gear can damage coral. Be safe and have fun!

Create a specific directory for each survey using this format:

YYYY-MM-DD [Location Name], [Vessel Name]

Place both the raw video files (.MP4 or .MOV) and the complete GPS track (preferably .GPX) into this folder.

Create a .zip archive of this folder.

During our pilot phase, please submit your data folder via a cloud storage link (Dropbox, Google Drive, WeTransfer, etc.) or direct email to the project coordinators. We are currently building a dedicated web interface for automated uploads and synchronization.

If you prefer to host your own data, you can upload your videos to your personal channel (YouTube, Vimeo,...) and simply send us the links along with your GPX tracks. However, proper metadata is crucial. Please title each video using this exact format to ensure we can match it to the GPS data:

2025-11-21 FIJ Vanua N - Navadra S 01 1m

(Format: Date Country Region - Location TransectNumber Depth)