I have no knowledge or experience with the SeaBrake, and cannot comment on it. However, a few general comments may help
A few years ago, I researched what might be appropriate for my Swanson 42. There is extensive literature and web sites on the topic of drag devices. And much debate on forums
such as this, with many opinions, like anchor
debates. I reached the conclusion that a drag device from the stern is the most appropriate for a canoe stern, heavyweight, full keel
cruiser such as the s42. The high stern and centre cockpit
of the s42 are important factors..
I bought a Jordan Series Drogue from Series Drogue in Melbourne. The proprietor, Bryan Glover, sails
a Swanson 28, and reckons the series drogue is ideal for the cruising family
of swansons, though he might be a bit biased.
For the series drogue, the attachment points for the bridle are crucial. In terms of spacing, and strength. Working from notes from Jordan and from Glover, it seems in a worst case scenario, that the individual arms of the bridle on a Swanson 42 could be subject to a load of 9 tonnes. Deck
cleats and mainsheet winches are not up to that sort of load. The recommendation is for purpose built plates on the hull
, fastened similarily to chain plates, but running horizontally.
I don't know if your SeaBrake would generate the same sort of load as a series drogue.
In Banjo's case I fashioned the attachment points as follows. The gunwales are about 38mm thick, solid glass; there are scuppers just fore and aft of the chainplates; so I fashioned a bridle to go round all that (actually, Glover made it up for me, out of 27mm nylon braid). I consulted extensively on this attachment point, including the builder
of Banjo, and there is no doubt it is strong enough. However, I am not happy with it...too much sweep over the stern. But it also gives me a strong point if I ever need to be towed. At some stage I will put plates on, as per recommendation.
I have trialled the series drogue, deploying it in 25knots, and retrieving it the next day in 12-15 knots. Even in that light wind, retrieval was hard. Don't under estimate the forces at work.
I would counsel against deploying your SeaBrake from the bow, especially as I get the feeling that it is meant to slow you down, rather than stop the boat completely. There is extensive discussion on this in the literature.
While my faith is in the series drogue, I also have recently bought a Para-Tech sea anchor
(made in Melbourne). It is meant to be deployed from the bow and to stop the boat completely. No experience with it yet, only bought it because it was so cheap
Don't know if this helps you any. BTW, I would suspect that the 12mm poly line is for retrieval??
I would strongly suggest getting onto SeaBrake for instructions, load factors, etc.