by GreenLake » Fri Aug 15, 2014 4:38 pm
Looks like the link works now.
Here are my personal thoughts on the device. It's a nifty idea that could allow significant flotation at the mast top with limited windage, because the compact size of the device prior to inflation.
The smaller of the two devices gives > 5gals of flotation. That would seem enough for the DS. A catamaran might need more. (I base the estimate on the fact that it would take about 5gals of water to balance the hull on the hard, that is hold the mast horizontal with the weight of the hull suspended on a gunwale. It would seem that this is a good approximation of the magnitude of forces that would act to turtle a boat that has capsized).
The device represents significant weight, which, positioned at the end of a long lever arm will require between 5-10 lbs of additional crew weight to balance (50% more for the larger size). In addition to the weight of the device comes the weight for the recommended dedicated halyard and halyard block. (I remember having done the exercise once and come with a ratio of between 1:5 and 1:10 at 30 degrees of heel. Feel free to re-calculate and correct).
The price quoted for European customers is € 149.00, and includes 19% VAT which is not due on export, the US price of $324 comes to €240.00 at today's exchange rate, and presumably does not include tax. Subtracting the European tax, the US price seems to allow for a markup of $100.00, which is a bit steep. Even if the quoted price included shipment from Europe, there seems to be a considerable markup over the end-user price.
One downside that I see is based on the active nature of the device: it comes with a significant need for maintenance. The instruction manual suggests to check the trigger for device each time it is used and another, more extensive check every season. Finally, every two years, you are supposed to send the unit in for service.
It seems that a floatation pouch attached to the top of the sail and / or some foam attached in front of the mast top (aerodynamically shaped) would result in a passive system of comparable or better characteristics as far as flotation benefit and costs in terms of windage. With the added benefits of much less expense and that it would be an "install and forget" solution.
My 2cents.
~ green ~ lake ~ ~