The most common and most likely answer to this crossword clue is the 8 letter word FERRYMAN
I've seen this crossword clue in Financial Times
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More clues leading to the result FERRYMAN
- One taking over companies he’s floating?
- He may get into a row transferring charges between banks
- Spooner's jolly enthusiast who may operate in the underworld?
- Spooner’s happy supporter works on water
- Spooner’s cheerful admirer – he’ll get you across the water
- Transport worker‘s key blunder — many must be worried
- Spooner’s cheerful enthusiast? He’ll get you across
- The offer of money may make him cross
- Iron rail's initially carried by railway employee to river transport operator
- Spooner’s tipsy enthusiast is steerer of boat
Buddy explains!

The straight part
We know that "steerer of boat" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case steerer of boat = ferryman.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.