Why has no-one mentioned?
I am a huge fan of moorings over marinas, the sailors slum. However I NEVER trust a mooring I didn't build or inspect before using. Chains rust, ropes rot and some are just not up to the challenge of holding either a 30,000 pound boat, or a bleach bottle depending on how old/insufficient it really is. In addition to how well it is built you also have to be careful about how you lead your lines. I built a "Bomb Proof" mooring a few years ago, and had complete faith in it. I was the week link. I led the two 3/4'' lines that connected to two 3/8'' chains by a massive galvanised swivel, through my hawse pipes and onto a solid post. That was my undoing. In a storm, 72 knot gusts recorded nearby, the lines chafed through at the pipes. I had chafe gear in place, leather and exhaust hose. Had I led the lines over the bow roller I would have been fine. Instead I had a winter in a boat yard and a big insurance premium increase. All that said if you don't know for a fact that the mooring you are about to tie to is in good shape, drop your anchor, thats what they are there for, just use lots of scope.
PS is there a way to change my screen name? One typo and I am going to look like an idiot every time I post.