I feel your pain Sept. I don't know about watchman gobies, but I had a Diamond Goby until yesterday, a.k.a. Orange-Dashed Goby, who was a blast to watch. He would come out and zip around the tank, then dive into one of his many caves he dug under all my rock. At feeding time, he would go anywhere he could to snatch some food. When I got him, it took him about 4 1/2 days to show himself, I started to think he had died. He was doing great, just a bit shy. My kids even named him Coby the goby. Then he didn't come out to eat yesterday morning. Unfortunately, I had a gap in one corner of my tank where my filter is - only about an inch-and-a-half wide and as long as my filter. Wouldn't you know it, the goby found it. Then, unfortunately, I found him - behind the tank dried up.