Public Template — Focused on Detecting PRC Grey-Zone Activity in and around Japan
This guide provides ordinary residents, fishermen, hobbyists, students, and community volunteers with simple tools to observe and document PRC maritime activity near Japan’s waters, including the Senkaku Islands, Okinawa approaches, Kyushu, the Sea of Japan, and other areas where China frequently conducts grey-zone pressure.
All tools are free and require no prior experience.
1. Purpose
To give the public a clear, transparent method to monitor and document PRC naval, coast guard, maritime militia, and fishing fleet activity near Japanese waters — including incursions, intimidation, surveying, “research” missions, and illegal fishing.
This provides awareness and contributes to a safer maritime environment.
2. Free Tools (Beginner-Friendly)
AIS Tracking
MarineTraffic
• Search by vessel, port, area, or company.
• Use to view Chinese Coast Guard, “research vessels,” and fishing fleets approaching Japanese waters.
• Shows speed, direction, loitering, swarming, and AIS on/off behavior.
VesselFinder
• Secondary AIS source.
• Useful for confirming MarineTraffic sightings or filling signal gaps.
Satellite Imagery (Routine Updates)
Sentinel Hub EO Browser
• Shows Chinese vessel clusters near Senkaku, Okinotorishima, Yonaguni, etc.
• Useful for detection of PRC survey vessels, anchored fleets, or new installations.
Mapping
Google Earth / My Maps
• Mark points around Senkaku, Okinawa, Amami, Tsushima, Hokkaido.
• Save coordinates and track repeated appearances of the same vessels.
3. Using Your Local Coordinates
- Open your map app and obtain the latitude/longitude of the area you care about.
- Copy the coordinates.
- Paste them into MarineTraffic or VesselFinder.
- Zoom out slowly to identify Chinese vessels entering or circling the area.
- Bookmark or save locations showing repeated activity.
This works from anywhere in Japan, including remote islands.
4. What to Watch For
These are observable indicators only — no speculation required.
PRC Vessel Types Common Near Japan
- China Coast Guard (especially 1300–1500 ton class near Senkaku)
- Maritime militia disguised as fishing boats
- Large distant-water fishing fleets
- “Research” and survey vessels
- Intelligence-gathering ships
- Naval auxiliaries
- Tugs and support vessels
Behavioral Indicators
- Vessels lingering or circling near the Senkaku Islands
- Survey or research ships tracing grid-like patterns
- PRC fishing fleets operating unusually close to Japan’s EEZ
- AIS turned off near sensitive waters
- Groups of vessels moving in formation
- Coast Guard hulls escorting fishing or militia vessels
- Loitering just outside territorial sea limits (12 NM)
- Vessels approaching SDF/Coast Guard routes
PRC Identification Clues
- MMSI beginning with 412 or 413 (China)
- PRC flag
- Vessel name prefixes like “Hai Xun,” “Yuan Wang,” “Hai Yang,” “Cuao Yu,” etc.
- Recurrent ships seen near Senkaku: CCG 330x series, 21551, etc.
5. Standardized Japan-Focused Report Format
Use this format for clarity and consistency:
Location
[Example: Senkaku Islands / Yonaguni / Tsushima Strait / Coordinates]
Vessel
[Name / hull number / “Unknown”]
Type
[Coast Guard / Maritime Militia / Fishing / Research / Survey / Intelligence]
Flag
[China]
MMSI / IMO
[If available]
Coordinates
[Latitude, Longitude]
Time
[Local time + date]
AIS Behavior
[Normal / intermittent / off / irregular]
Movement Pattern
[Loitering / circling / cluster / approach / drifting / formation]
Evidence
– MarineTraffic screenshot
– VesselFinder cross-check
– EO Browser image (optional)
Notes
– Approx. distance to Japan’s territorial sea line
– Whether vessel is near a known hotspot (Senkaku, Okinotorishima, etc.)
– Weather/visibility
– Presence of additional PRC vessels
6. Good Practices (Japan-Specific)
- Use UTC+9 for timestamps.
- Save recurring vessels — many PRC Coast Guard hulls return to Senkaku weekly or monthly.
- Avoid personal data; keep reports fact-based.
- Share both coordinates and screenshots for clarity.
- Check both AIS sites when a vessel loiters suspiciously.
- If AIS shuts off, check satellite imagery for the date range.
7. Example Report (Japan)
Location
Senkaku Islands — 12.4 NM NW of Uotsuri-jima
Vessel
China Coast Guard 3303
Type
Coast Guard
Flag
China
MMSI
413330303
Coordinates
25.812° N, 124.300° E
Time
2025-06-14 — 10:15 (UTC+9)
AIS Behavior
Normal signal but slow maneuvering
Movement Pattern
Loitering near territorial sea limit
Evidence
– MarineTraffic screenshot
– VesselFinder confirmation
Notes
– Second PRC vessel observed 5 NM east
– Clear weather
– Similar incursion pattern observed previous week
by Miao_Yin8964