With 344 ft (104.85 meter) length over all Nasser al-Rashid's superyacht is so big that she's even visible on this low res photo from space. Normally berthed at Port Hercule, Monaco or Club de Mar, Palma de Mallorca, she can be seen here cruising off Emerald coast.
See also
http://en.wikipedia.org/wiki/Lady_Moura