Just bought a used Tiger Shark and was looking at the coil connection. I am used to other underwater detectors, but have never seen one where you could change the coil. Anyways, it appears to plug in as any other detector (5 pin). Then you just tighten up the serrated ring. Is that all there is to it?? Is that a waterproof seal?? No O ring or anything?? Just want to know before I sink this baby. Please help!!!