Re: any theorys??
That boat was a charter, not a rental. The "captain" really messed up, I'm sure he's going to be in a lot of legal trouble for a long time.
I have the same boat. It is a Macgregor 26s model. It is 1650 lbs dry, and carries 1200 lbs of water ballast, for a total of 2850 lbs, plus everything that's added to the boat. It's the water ballast that makes it self righting. The keel is a "swing keel". It can pivot up into the hull for shallow water, or trailering. IT DOES NOT LOCK DOWN.
It also does not have any lead weights in the keel. It's only for making the boat track while sailing. I have had 5 adults on my boat in 15-20 mph winds and no issues. I think that is all I'll ever carry because it gets too crowded, but the boat feels like it could do more.
That guy had 10 people on board. DUH!. I saw a picture of the boat from the day before the accident, and it didn't look right. Like it was listing really bad under power and the jib, no main. The charter people say the boat is moored in the water, so it doesn't seem likely that the ballast tank was empty, but the boat could have been taking on water, making it unstable.(one would hope that if they used it a lot they would know it had a ballast tank!)
Under normal circumstances, it takes a couple hundred pounds of down force to hold the mast over to water level. (you can see the video on the net from Macgregor advertising, on U Tube) When released it pops up really fast. It does not turtle. Not even close.
There was definitely something wrong with the boat in addition to being grossly overloaded. If it would not have been full of water, and the ballast tank full, it would have righted itself after everyone fell out, and it didn't.
There is nothing wrong with these boats, and the swing keel and water ballast allow you to do things that fixed keel boats just can't do, like use a standard boat ramp, and go right up to a beach for camping. Not to mention it's a 26 ft boat that you can trailer with a mid size SUV. I pull mine with a Ford Explorer, with a 6 cylinder motor.
Jim