Honeymoon Funds As Wedding Presents

My finace and I both are very grown and in our thirties. We don`t want to register for traditional wedding gifts because we simply don`t need anything. However, we are planning an island getaway honeymoon, and we would like to offer people who would like to buy us gifts the opportunity to help us pay for our honeymoon instead of buying us traditional, extraneous merchandise. How can we politely and tactfully ask/inform our friends and family of this particular request?