This excerpt taken from the RIG DEF 14A filed Nov 3, 2008.
Under U.S. tax law, holders of shares of Transocean-Cayman generally will not recognize gain or loss on the exchange of such shares for shares of Transocean-Switzerland in the Transaction. Under Swiss tax law, no tax is due for non-Swiss holders of Transocean-Cayman shares on the exchange of Transocean-Cayman shares for Transocean-Switzerland shares in the Transaction. Please refer to Material Tax Considerations for a description of the material U.S. federal income tax and Swiss tax consequences of the Transaction to Transocean-Cayman shareholders. Determining the actual tax consequences of the Transaction to you may be complex and will depend on your specific situation. You are urged to consult your tax adviser for a full understanding of the tax consequences of the Transaction to you.