On Thu, 26 Aug 2004 17:24:51 GMT, "Gary"
wrote:
Is there a general rule of thumb for determining how strong your dock lines
should be?

I have a 34 foot boat that weighs somewhere in the neighborhood of 19,000
lbs. I want to buy some dock lines to carry onboard for tying up at fuel
docks or the occasional restaurant etc. when I'm not in my slip. I really
don't want to have to untie the lines at my slip every time I leave, since
I'd have to find just the right adjustment again every time I return.

There are LOTS of sizes and strengths of line out there. What should I
really be looking at?
=============================================

My old boat was about the same size and weight (33 ft 23,000#) and we
used 5/8 inch nylon lines for short term tie ups. For longer,
unattended docking I'd recommend 3/4 inch. My mooring lines were 7/8
with lots of chafing protection. Never had problems with any of that.

I once had a dock line break on a 34 ft sailboat in calm wind
conditions. It was 1/2 inch dacron braid (low stretch compared to
nylon). The breakage was caused by interaction of the boat with a
floating dock in response to a wake. The boat and dock were moving in
different directions and at different rates, causing the dock line to
snap like a rubberband with no warning. Fortunately I was next to the
boat when it happened and was able to quickly re-tie. All that is
offered by way of explanation for my conservative approach and use of
nylon line.