When in Sipadan, there is what they call a "Turtle Cavern" very close to the arrival area of the Island. On one day the DM of the boat announced that he would take everyone in there to see the turtle skeletons within. The cavern was at about 65ft of depth. I did not have my light or a reel with me that day & refused to go in. I caught a lot of flak over that from those in my group on the boat, but not having the proper equipment, I wasn't going to do it. I just hung out at the entrance,..... waiting. In the end everyone came out & was fine. When the head instructor leading the trip (a cave diving instructor), was quite upset when he found out (he was in another boat with more of our group that day). He basically informed tose that went in that they put a bullet in the chamber, spun it, pulled the trigger & got lucky. A couple days later when my instructor was on the boat it was announced that we would go to the cavern again for those that didn't get to go the first time, plus the head instructor wanted to get some video footage of the cavern. I had my light & a cavern reel, that day. I tied it off at the entrance & went in with my instructor & the DM. About 3/4 of the way in, my spool ran out (at 140ft). I just waited there. My instructor went on another 50ft or so & video'd the skeletons. We kept in sight of each other & in communication through our lights. In a few moments he came back & we headed out. To see the skeletons you had to go about 200f into the cave. Yes, you could barely make out the entrance from there, but that's a long ways to take untrained people just to see some turtle skeletons.