This is Beneteau which means the hull would be very shallow, hulls own draft is less than 1'. From the images it does look like she sits quite abit lower than usual (though not 4' by any measure, at 4' in Benny water would be up to everyones neck and the boat would be sitting exactly 4' under water).
However, it is worth noting that she is listing to one side, and water may be on that side, so the side towards the camera looks higher while the other one sunk more.
In any case, as with any salty rescue story, the seamonster is 3 times as big - there may be a foot of water or so in their boat. Since Bennies don't have a bilge, fairly small amount of water will flood the cabin, float the floorboards and likely kill the engine too. Without the engine, their batteries would not be able to run the bilge
pump for long (and depending on how wiring goes - a short might prevent them from running at all).
I had a silly incident with my prev. Beneteau - on a first day of sailing, just as we left Annapolis water started flooding in at a very high rate. I had 1"-2" inches appear every minute or so - bailing with the
pump or the bucket wasn't fast enough. My floorboards turned into rafts

and it all looked very very scary - especially if you can't find the source and have to wade ankle deep in rising water with stuff floating around. Turned out - silly design (or, more likely, modification by PO - it could have never worked) - shower drain which is firmly under water level was connected to sink drain and sink drain seacock was open, so water entered from the shower. But the point is - even with 3/4" seacock open and flooding the boat through a hose - water levels rise very quickly, and in a boat without a bilge stuff will float right away.