Here is what I did for my RSVPs, I like yours but feel free to steal any of my wording it's a combination of things from different sites:
Please respond by
July 1, 2009
Or you’ll have to walk the plank
Full Legal Name(s) and Date(s) of Birth (for sailing or non-sailing guests)
____________________________
____________________________
____________________________
____________________________
_____ We will sea you for the entire cruise
_____ It’s a shore thing, but we’re not sailing
_____ Sorry we are all tide up that week
As for your reception details what you have is fine but I'll give you other suggestions and you can use them or not I won't be offended
Please join the bride and groom following the ceremony on the pure pink Bermuda sands for beverages and an intimate cake cutting. The fun doesn't stop there, our transportation will bring us back to a delectable dinner aboard the (name of ship).
The bride and groom are also arranging an casual Charolette celebration in September, more details to come.