It would depend if you were talking about fresh or saltwater diving and how much you weigh. In my experience I have to wear 36 to 42 pounds in fresh water and I weigh 205. I am on a local dive rescue team and all of the team members will wear the 42 pounds to make sure that we stay on the bottom when we are doing a rescue. Some of the team members have said that they have a hard time in the 15-20 foot range like you are talking about but we found that if they used some older underwear that problem seems to go away. So you might try adding a pair of ankle weights and as the underwear gets older you might try removing some of the weight. Sorry that I canít help out any more but I donít think that is too much weight unless you are having a hard time with the drysuit not giving you enough lift when you are wearing the 40 pounds.