Anchorage Adventures in Newport

So we had a bit of adventure at anchor yesterday.  The winds have been  clocking around several times which means the anchor has to reset.  So, yesterday afternoon Christine decided it was time for showers, so the only way to make hot water right now (since our AC water heater element is shorted) is to run the main engine.  Like a good first mate she knows the engine likes to work against a load even at idle, so she starts the engine and throws it into reverse.  Normally, it should just come to the end of the anchor rode and hold there, but surprise, we start dragging anchor into the mooring field.

So, we count our blessings that we were both on deck when we dragged.  We needed to take on some water anyway, so, we pull up anchor and off to the water dock.

On return it is just about sunset.  Another boat has taken our previous spot so we go hunting for another position.  We think we are getting pretty good at this anchoring thing now, so we find what looks like a good position in about 20' of water and I put out 90' of rode and we back down hard to set the hook.

A little while later the wind shift 90 degrees and I have this ESP that something is wrong.  I poke my head out the companion way, and low and behold, the boat that was 100' away is now right next to our port side.  Yikes!

I jump out on deck with a bumper and try to fend off, but my bow sprit is just crossing his lifelines. So I give a shout since I see their cabin lights on and the couple springs to action in their underwear.. He fends off while I attend to the rode.  Neither of us is dragging.  It is case of different scope.  He had over 130' out while I had only 90', so when the wind shifted 90 degrees he swung right over to me. The solution was for me to let out more scope and confirm that we were set by backing down on the rode again.

It is one of the mysteries of anchoring.  How are you supposed to know how much scope the neighboring boat has set out?

Wouldn't it be nice if there were some kind of flag system used in this situation?  Just pull into a crowded anchorage, observe the flags on other boats, then set your scope accordingly.