This lovely classic yawl is Giselle of Iken, a John Alden design, number 949KK, built in 1962 by Halmatic - GRP hull and wooden coach roof.
LOA is 38 feet, beam 11 feet and draft with the center board up a mere 4 feet. The Alden web site says that the name was changed to "Virtuous and Evil" so presumably a later owner has changed her back to the original name.
Thanks to Robert Stopper
56 minutes ago