Looking for 2-4 to join on 7-26 private boat

We booked out cruise pretty much last minute and found a boat that's open to snorkel and go from St. Kitts to Nevis. It's a group of 4 of us from ages 36-48 checking to see if a group or 2 or 4 would like to join us on a full day tour. Here is the link. Anyone sailing on Carnival Splendor interested??http://www.ptcharters.com/charter-options/

What would the date be?