I'm fairly light at ~160lbs(73kg) and have had difficulty pulling the Viper up in lighter air. Any wind or waves and its not too bad.

One thing I've noticed is when sailing with crew, just them being on the lower hull and not necessarily pulling on the righting line the boat comes right up. I wonder if the extra weight pressing the hull, (over singlehanded), in the water helps slow the drift making it easier to come up?

Dan and I sailing at 385 didn't have to use the righting line when the wind was up, just pull on the dolphin striker.