The most common and most likely answer to this crossword clue is the 7 letter word RIPTIDE
I've seen this crossword clue in The Daily Telegraph
R
I
P
T
I
D
E
More clues leading to the result RIPTIDE
- Split, make changes over stretch of turbulent water
- Problem for swimmers with tendency to rush at the start
- Danger in the ocean involving journey around island port
- Uncontrollable water pressure I tried failingly to contain
- Change lighting control around dangerous current
- I quietly tried struggling round strong current
Buddy explains!

The straight part
We know that "strong current" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case strong current = riptide.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 RIPTIDE mean?
RIPTIDE noun- A particularly strong tidal current
- A rip current which may carry a swimmer offshore (the term rip tide used in this sense is a misnomer).