### Clue: Naval officer and author having destiny on island (4)
### Answer: LOTI 
 ### Explanation: Definition: Naval officer and author
A charade of LOT ('destiny') plus I ('island'). Fortunately a simple wordplay for the defined French naval officer and author Louis Marie-Julien Viaud, who wrote under the pseudonym . I hadn't heard of him either (with apologies to those who have read him).