During the morning of 26th DJL was doing their first dive of the day at one of the local deep dive sites Hin Pee Wee just off sairee beach. As we jumped in to the water and took a quick glance below we could see straight away we were in for a great dive as the visibility was amazing at least 30 meters. Once we had descended me and my open water group headed south just beyond the pinnacle as I looked below I noticed a fishing box net and a large shadow moving along the bottom. I turned to my student and pointed for them to look down, at first we thought it was a shark as I have seen black tips around that area many years ago, but I could not see any black on the tip of the dorsal fin and it was difficult to tell what it exactly it was as I was at 17m and the “shark” was at about 25m. During the dive we were being filmed and the videographer had caught the “shark” on camera, when we got back to the shop we checked the footage but we were still unclear what the un identified fish was and due to the shape of the face I was starting to believe it could be a very big Cobia. The following day DJL went to the same dive site again and there was another sighting in the same place. This morning I was teaching Deep Specialty with the Divemasters which was great so I could get deep and get a better glimpse! We were correct it was not a shark it was a Cobia. A Cobia is not from the Shark family but from the Tuna family this is due its extended elongated dorsal fin which means it denotes it to the Tuna family. Hopefully this cobia will keep hanging around at Hin Pee Wee because he’s very interesting to look at.