I owned a 45 foot racing sailboat in partnership. We alternated weekends (and races) and one Sunday AM, I looked out the apartment window at the marina and "Speculation" was back in her slip, but the port upper shroud was slack. I walked over to the boat, there was about 3" of stretch of the port upper. This is a huge amount for a 5/16" SS cable to stretch. There was some other damage to the foredeck and the spinaker pole inboard lift winch had been torn off its base on the mast (5 5/16" SS bolts sheared). It turns out that the other partner was rounding the East End of Catalina about about 2AM and for some reason there was a very strong gust from about 180 degress of where the prevailing wind was comming. The spinaker was caught aback between the forestay and the mast--so I suspose that one might say that there was some lateral mast loading--but I suspect that most of the load was at the masthead. The boat was knocked down, the spinaker pole lift broke, and the pole was driven down its track to knock the winch off. When we replaced the upper shroud, we had the cable tested. It began to yield at over 10,000 lbs load. There was no other damage to the mast, fittings or boat. (and no-one was killed!)
On the other hand, I have seen back stay fittings fail because of crevice corrosion and the entire rig come down .
I think this is a bit of "guts ball" to do the water balloons under the bridge, but apparently it works for them. For me there are too many variables, including the actions of other boats on the ICW. Thanks for the thoughts on how the process begins--and this makes sense. If you think about this type of boat, its ballast, the 4,000 lbs is not much in comparison to the weight of the boat and keel.