The most common and most likely answer to this crossword clue is the 10 letter word ISLAND-HOP
I've seen this crossword clue in The Guardian
I
S
L
A
N
D
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H
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P
More clues leading to the result ISLAND-HOP
Buddy explains!
The straight part
We know that "explore by boat" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case explore by boat = island-hop.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does ISLAND-HOP mean?
ISLAND-HOP verb- To travel from island to island in a certain area, especially as a tourist to visit numerous islands.