Originally Posted by Simon Hawkins
As long as the end of the anchor line is attached to a strong point on the boat cant really see what difference if would make. If want to attach more line then all you would do would be to tie the other line to the anchor line by way of a reef knot. Of course you will know how much line to put out before dropping the anchor and therefore cant see the need to be adding more line once the anchor is down.
I use a rode with thimbles at both ends. To lengthen, I use a quicklink (not a carabiner, but the screw-closed chain link replacement thingie) as it is less likely to accidentally open. For securing to the boat, a carabiner.
Anchor, shackle (wired closed) chain, shackle (wired closed) rode, knot to get correct scope), carabiner, excess rode, float, carabiner attached to boat.
One other thing I do (which I feel is fairly imprtant for a dive boat) is to put a float on the boat end of the rode. Should something happen (injured diver, drifting diver in current, etc.), unclip the rode from the boat, toss the mess overboard, and motor off to handle the situation. Come back, recover the float, and there's your anchor. It also makes an OK ascent line for remaining divers in case you have to leave for whatever reason.
jky in California