Posted by Ross-O on October 26, 2004 at 14:40:48:
In Reply to: Ditto Chucks rules... posted by ptf on October 26, 2004 at 13:12:20:
Phil and I have lots of time on small boats. We usually put everyone in the water at the same time and leave the boat unattended topside.
The first order of business is to make sure you have enough rope/chain/anchor for the boat. Mark Wisch's book gives some good advice on proper ground tackle for fishing boats (http://www.pacificedgepress.com/). I'm no expert in this area, but it seems that what is considered adequate for a fishing boat and a dive boat (used in the manner that we use them) is probably 2 different things.
I doubled the amount of chain that Mark's book recommends and I now have 50' of 5/16"-3/8" chain and a 7.5kg Bruce with 260' of rope on my 24 Skippy. So far it seems to work well. 25' of chain was insufficient on my boat and we would drag anchor like crazy.
The second order of business on the dive is to check the anchor. I don't dig it in under power before the dive b/c I'm usually trying to drop right on or near a wreck and I don't want to drag it too far from the wreck should it not hook up immediately. Once I get to the bottom, I usually hook it into the wreck. If there's no wreck/rocks to hook to, I make sure the anchor is dug in and I want to see most all of the laying chain flat on the bottom. If I'm not fairly convinced that the boat will still be there when I come back, we call the dive or come up with some other idea to secure it. (this is so much scarier when it's your own boat!)
We used to use a liftbag on the anchor at the end of the dive to make it easier to pull. We would inflate the bag so that the anchor would just barely float off the bottom and the chain would make a U that dragged along the bottom. Kendall Raine & John Walker had some concerns that this practice introduced unreasonable risks and built a very good case for their point. Since this discussion, Phil and I have largely abandoned the lift-bag-on-the-anchor trick (and the fact that we now have a windlass also helps).
At the end of a dive we unhook the anchor and move it and the chain out into the sand or some other clear area. There have been several times when the current was ripping and it was obvious that anyone not on the line may never make it to the line when we unhooked. Keep an eye out for this.
If any of you more experienced guys have insight into anchor handling best practices, I'd love to hear them.
There's only been one time when were diving and returned to the anchor only to find a drag mark leading out into the abyss. Thank goodness that DonS had made it to the boat before us! That was a good lesson for me.
It's hard to imagine what happened regarding Colin's accident given the sparse details that are currently available. My heart goes out to his family and his friends. Hopefully someone knowledgeable of the situation will post a full report once all the details are known so that we can all learn from it. Nothing can make this tragedy better, but as with all accidents, the same thing happening again to someone else would make it worse...
Ross-O