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Mirabella V - believed to be the largest and most expensive yacht in the world - left Portsmouth on her maiden voyage in May

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A good head for heights is needed atop the �30m yacht's 90m-tall mast

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The yacht was made in Southampton for US businessman Joe Vittoria, the former head of car hire firm Avis

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The interior was designed by Mrs Vittoria herself

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The yacht headed for Mrs Vittoria's home town of Naples