My ten cents worth on anchors. West Marine "advisor" says 1/8" of line for every 7' of boat. That's 3/8" line for the R21 or R25, but I have 250' of 1/2" line plus 40' of chain on my R25. In the San Juans and Gulf Islands for the past 20 years on my previous boats I've always had 200' line, 40' chain and never yet had to pay it all out. I do have -- and often use -- a KELLET. This is a 10 lb downrigger ball that I have on a 1/4" line that, after anchoring, I allow to slide down the anchor line to lie near the chain & line joint. This significantly multiplies the holding power due to it's weight. It helps keep the chain on the ground which is where your safety is. This also allows you to use less scope in crowded anchorages in decent conditions. In bad conditions, use scope and kellet and life is much better. I have enough line on the kellet so that I can cleat it to the boat, but if it was deeper, I would attach the line to a fender and toss the whole shebang overboard. I have a snap shackle on my kellet and hook it onto the anchor line as well as the ring in the anchor locker so it doesn't go walkabout.
I am getting a second anchor line in the next week. I'm torn between 150' of 3/8" line and 20' of chain or pretty well a duplicate of what I have now. I'll probably go for the 1/2" line -- I guess my boat is worth the extra $50. My second anchor is a Fortress, which is able to be disassembled and makes storage easier. My primary anchor is a 10kg Rochna, the New Zealand anchor. I'm loving it.
Dave
"Lobo"