Is there a difference between קפטן and קברניט?
No, I think they both originate from foreign languages.
The actual Hebrew word is "רב חובל" if we are talking about a ship's captain
Is the pronunciation correct ?
(can't quite tell if this is voice recording or generated speech). The dictionary appears to suggest a hard ב (dagesh)
Well, קַבַּרְנִיט is the more correct pronunciation, but for this old Greek loanword the pronunciation קְבַרְנִיט with a soft בֿ is also widespread.
I hope his boat is ok!
”אוי לו לעולם שאבד מנהיגו ואוי לה לספינה שאבד קברניטה (בבא בתרא צא.)"