The open area at the stern--not part of the original design--was made possible when new engines,
two Allison aircraft V-12's developing 1100 hp each, were installed lower down in the boat's hull.
Whittell might have frowned at the idea of more guests, but he would have loved the thought of his
"Thunderbird" with double the horsepower, and a top speed almost twice what he'd dreamed of. . . .