Picture: Marstrom 90 in Vastervik Sweden
If you decide to build a Multi 50 there is a class rule to take into account. If you do so it is possible to compete with the boat in for exammple Route du Rhum La Banque Postale.
An Ultime is only specified as Overall length ≥ 60 feet without size limitation (at RtRLBP). A length of 70-75 foot would give it a fair chance to compete with the older ORMA 60:s and a fair change to sail it solo.
The material chooise is free but it would be wise not to use nomex/carbon in the hulls. You can build a large multihull more expensive or cheaper but before you decide think of the example of Joyon with Idec II and Coville with Sodebo. Joyon did choose a cheaper bulding process at Marsaudon in France and Coville the more expensive at Boat Speed in Australia. Until today it seems that Joyons choise was the smartest...
Links: http://www.routedurhum-labanquepostale.com/fr/s01_home/s01p01_home.php
