"...immersed into the ocean"
it sounds bad, doesn't it?

Dear Carol, Joe and Dean.

We take this opportunity of thanking you for the marvellous manner in which you chartered our deity (albeit no winch) and immersed into the ocean on Sunday, 7 September. Your kind support is sincerely appreciated.

We are overwhelmed by your support and commitment and this has contributed significantly in making our event a memorable and successful one.

Once again, a big THANK YOU.