Fourth S501 In Process At Tankoa Yachts Here is a look at the fourth S501 by Tankoa Yachts that is presently under construction. The yacht known as Project 'Elettra' takes its design from the drawing boards of Francesco Paszkowski. She is a sister to previous members of the S501 family being the latest of that class. The last yacht of this class was the very distinctive black S501 -hull three- called "Olokun" which launched in September with anticipated delivery in November. Below is the first hull, "Vertige".