Guppy is an extended Jeaneau Gin Fizz ketch. Because off this, there is more room for the solar panels and water releases more easily. Guppy is much heavier as a result of the many changes and extra equipment, and therefore lies much deeper.
Technical Details of Guppy
Length: 12.30 m (original 11.40 m)
Beam : 3.76 m
draft : 1.90 m (original 1.80)
weight : 11 ton (original 7.9 ton)
Guppy underwent many changes for the voyage, like heavier rigging, a deeper bigger balance rudder, many more winches, more tanks etc. etc.--too many to mention all.
More info here: http://zeilmeisjelauradekkerarchives2.blogspot.ca/p/voiles-et-voiliers.html