Scott & Others...
 
In some areas/states a commercial fishing license is needed for dredging. It
is best to check with the local marine fisheries dept. to see what regulations
there are in the area you plan to dredge.
 
My experience with dredging has been limited to the waters in the Gulf of
Mexico from 120 feet out to approximately 800 feet so what I have to share may
be somewhat different that in shallower waters but then again, the basics
should still apply.
 
There is nothing which will prevent the dredge from coming up against rocks!
Even when you have equipment for scanning the bottom you only have a general
idea of what it looks like (i.e., is it soft - sandy, hard - rocky, flat or
sloped etc.).  While you can easily tell if there is a drop off or ledge that
you've come up on, it isn't all that simple to tell if there is a small break
or a rock that is large enough to hang up on.  Or for that matter, an anchor
that someone lost!
 
In order to keep your dredge on the bottom your cable or rope should have
approx. a 3:1 ratio to the depth you are working.  AND your speed is critical!
We've found that at most depths you should be at no more than 1.5 knots(which
at times feels like you aren't even moving), any faster and the dredge comes
off the bottom.  With practice you will be able to feel when you are on bottom
and exactly when you speed up and break contact. Just place your hand on the
rope and you'll be able to feel it tapping along the bottom.
 
Another advantage to going slow is that while you may find yourself hung up on
a rock, you won't be "slamming" into it.   The dredge can act as an anchor if
it hangs up or if it is too full so you need to be prepared at all times to
quickly take the boat out of gear and attempt to free the dredge.  Sometimes
it is as simple as backing up while pulling in the slack and other times you
need to come around so that you are pulling away from the direction the dredge
is hung.  Until our last trip in August this was always successful.  But then
our favorite dredge hung tight and no matter what we tried it wouldn't move.
The connector between the cable and chain on the dredge finally snapped and
there it lies about 750 feet down.  Hopefully our new dredge will be ready
this week so that we can get another trip or two in before the winter weather
pattern sets in making it too difficult to dredge.
 
Some people attach an additional rope to the back of  the dredge to be used
for pulling it up if the main rope breaks.  You have one rope attached to the
winch and the other one simply plays out off the deck and is tied off once you
are on bottom.  If the winch rope breaks you can either pull the dredge in by
hand or attach the secondary rope to your winch.   In our case this isn't
practical but might be a good thing for you to use in shallower water.
 
Hope some of this helps!
 
Em Sower
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Nokomis, FL