It has to be labeled for marine use (approval) by USCG. I tried to zoom in on your photo and it does look like those are labeled for marine use. Look at the right side of the label near the "electrical equipment" icon. (Lots of people think marine extinguishers have to be white. That's a misnomer. It can be red or white - so long as it's USCG approved on the label.)
The only downside to these dry chemical ones is the horrid and electrically corrosive mess they leave behind. 😵💫. Yes beats a fire. You can get better ones, for a price of course:
Comments
https://www.fireboy-xintex.com/portable-clean-agent-fire-extinguishers/
food for thought.
PC BYC, Holland, MI