I always have anchor watch it does not matter what the conditions are. Here in the med the weather can change from 5 knots to 45 knots in 5 minutes. If the weather is calm then myself or a crew member will sleep in the wheelhouse. We do 4 on 4 off. When we were in Croatia/Turkey in a well sheltered bay with either one anchor or 2 anchors out with stern lines going onto land then we sleep in our cabins. Most Captains quarters have instrumentation in them. When ever I am at anchor I can never sleep peacefully.