Can't believe no one chimed in with this one yet: Anse Chastenet in St. Lucia is BOTH a quintessential honeymoon resort on a honeymoon island destination, AND a notable dive resort. Budget allowing of course...
This is a dive destination where I tell folks to NOT plan on diving all week - leave some quality time to explore the island.
There are multiple pricing options there, and the owners love to cater to divers. Get one of the hillside rooms if $$ allows.
Anse Chastanet Resort | St Lucia Resorts | Caribbean's Most Romantic
Anse Chastenet was my first thought also, with the same caveat on budget. I wouldn’t honeymoon at many places I like to dive, and Anse Chastenet is one of only a very few places that strikes me as a great honeymoon spot where it is also worthwhile to dive.