Posted by Gerry Smith on February 07, 2002 at 14:05:16:
In Reply to: Wreck Tie-In posted by Tyler on February 03, 2002 at 13:54:07:
Like Max said, the key to anchoring to a wreck is chain. The heavier and longer the better. Use a larger anchor and longer/heavier chain than recommended for your boat. Another tip is a Bruce or CQR type anchor, Danforths will "sail" u/w if used with line, and they tangle with chain as the chain drops faster than the anchor.
Locate the wreck using GPS/Loran or visual lineups. Spend some time over the wreck getting a mental picture of the bottom topography with sonar (remember what you see on sonar is everything within an 8 to 15 degree cone below your transducer, not necessarily what's directly under you.)
Use GPS/WAAS, DGPS or "seat of your pants" to determine set and drift. Head across the center of the wreck on the reciprocal of the set. Once past the wreck, (well past if drift is large) drop the anchor as quick as you can without causing it to tangle in the chain. When you feel it touch bottom, let out enough scope to avoid "kiting" the anchor over the bottom but not enough to allow it to set in the sand. Slowly drift or back down over the wreck until the anchor snags it. After some experience, a good deck ape can feel the anchor bounce along the bottom and the chain drag over the wreck. He can also tell the difference between the anchor setting in the bottom and snagging the wreck. Let out additional scope for safety (don't need too much with all-chain rode and a solid snag.)
The first diver down verifies the security of the snag and the best heading to free the hook when time to go home. If the snag looks shakey, use a line/reel so you know when it comes loose. If necessary, the last diver up frees the hook from the wreck for easy retrieval. If you can't get the hook back at the end of the day, buoy it off and come back for it. Too many stories of bad consequences to "bounce it for the hardware".
GS