SAF: No, the rings won't get in the way of the housing, but make sure you get the small ones, about 1/2" across. At least, they don't get in the way of my PT-018. Since this is my first underwater rig, I can't claim any knowledge of other housings, or definitively answer Warren's question about the PT-015. I would think, however, that since the PT-018 and PT-015 are made by the same manufacturer, they would hold the camera in a similar fashion. My C-750 is held securely in place by internal plastic braces extending from the sides of the housing, which leaves about a fingertip's worth of room between the camera body and the walls of the housing. That's more than enough room to accomodate the split rings attached to the camera, which hang almost flat against the sides of the camera body when not attached to the strap. I found a PT-015 photo online, which I've attached here. It looks like there's plenty of room in there to accomodate the rings. If they make them all the same way, I think you could probably get away with this technique on any of the PT series.