A few nice search engine listing images I found:

sponsor flag #5842
search engine listing
Image by Nemo’s great uncle
• ????(Yamm?) = "Yanmar" ← manufacturer of diesel engines, fishing boats, etc.
• ???(tairy?bata) = "great catch flag" ← These were originally raised by fishing boats returning to port with a bumper catch.
→ two more antique examples
Flickr photos with ???

sponsor flag #5839
search engine listing
Image by Nemo’s great uncle
• ????(Yamm?) = "Yanmar" ← manufacturer of diesel engines, fishing boats, etc.
• ???(tairy?bata) = "great catch flag" ← These were originally raised by fishing boats returning to port with a bumper catch.
→ two more antique examples
Flickr photos with ???