Ha ha ha ... The man who wore a helmet like in the photo above looks unique, because it is rare and unusual. Usually, a helmet is used when riding a motorcycle, not when rowing a boat.

I think he was wearing a helmet for not carrying a hat to protect his head from the sun. If we look at it from the funny side, he wears a helmet to keep his head from being pierced by a bird that often stops at the reservoir.

However, the most likely possibility is that he forgot to remove the helmet on his head after parking the motorcycle, then down to the reservoir to check the fish cages or cultivation. And, if you see the positive side of the man wearing the helmet, let's just say it as a form of "socialization to motorcycle users so do not forget to wear a helmet because it is very important to keep the head in case of a traffic accident".

Thanks @vannour has shared a unique photo.