[quote=Edchris177]Interesting spot, I didn't know there was a sailing community on that lake. I grew up in the hot dry S W Alberta, spent more time in Waterton than Banff, & though Waterton Lake is a good size it is too bloody cold for much swimming!
We sail a Nacra 5.0 & a 5.7(just under 19'). I found it very hard to PP the 5.7, as long as you get your weight towards the rear. Trap out as far back as you can get, & have your crew right with you.
The shorter 5.0 will PP, if whipped hard on a broad reach. Last summer I was sitting as far back on the hull as I could get, it lifted 3 times, but the Nacra has good forward flotation, and as long as I released some sheet, (I was already traveled out to the hiking strap) it came back down.
I have experienced what you went through,(not breaking the leg)the boat lifting its stern, & by turning further downwind, power drops...the stern comes down, speed drops way off. Once the fear subsides a bit you can steer back onto a faster line. I think the experienced racers have to be good at staying on this line, if they don't/can't they are not going to win at the higher levels.
I find that many sailors can hold speed on a beam reach, few can sail well downwind. (I'm not saying I'm good at it, I would be massacred by the experienced racers)
It is an exciting point of sail, fast, but I only do it when the wind is in a more steady state. In the extreme gusts you must experience in a lake located in the Chinook belt, & that close to the mountains, it will be a challenge. If you only had to deal with velocity changes the problem would be more manageable, but when it moves 90* or more, then back, you are going to do some swimming. Many years ago I remember being at that tiny grass airstrip in Banff, the wind socks at each end were pointing AT each other.
If you are sailing downwind it can be difficult to head up to dump power, it just takes to much time. As you turn you have to pass through a position of more power, before you start to head up, & it is easy to go swimming.
The telltales will show instantly if you are going to dump, or increase power as you start the turn. If I sail downwind in strong winds, I keep it quartering from the rear,(telltales on the bridal at 90* to hulls) & you can dump power & prevent a PP by releasing sheet/traveler. However in 90* wind shifts all bets are off.
If you had a foot under the hiking strap it would be easy to experience a twisting moment, however I don't believe you have to "twist til it breaks" to experience a spiral fracture. Decades ago a buddy jumped off a small bank into a swimming hole, the water was not deep enough & when his foot hit bottom he sustained a spiral fracture. Hope your bones are younger than mine & heal quickly.[/quote]