So, I have been looking around for a few days now into finding what title the Phoenicians, or at least the Carthaginians, used for their ship officers.
My interest is due to the fact that the word captain, derived from Ancient Greek, is similar in many European and Near East languages, and was wondering if the Phoenicians used a similar term or if it differed.
Captain really has two sources:
These two words got confused at some point, and the first gave us the form of the word captain, the second the specific meaning. Both of these words have very transparent etymologies in their respective languages, so if they turn up in unrelated languages they must be loans from (a descendant of) Latin or Greek or some other language that previously loaned it; Arabic كبتن kabtin and Turkish kaptan certainly are. The meaning of captain as a naval officer definitely postdates the extinction of Punic by hundreds of years, though, so it cannot show up there at all.
One possibly attested Phoenician term for 'captain' is rb (cf. Hebrew רַב חוֹבֵל raḇ hôḇēl 'captain'). As in Hebrew and other Semitic languages, it certainly primarily meant 'chief, lord', but Krahmalkov, in his Phoenician-Punic Grammar (I don't have access to his dictionary just now), cites a papyrus from the 4th-3rd century:
[ʿl pn b]dbʿl rb ḥrmnym wʿl pn ʾš šlḥr[mnym]
Before Bodbaal, rb of Hermonim, and before the people of Hermonim
Hermonim might be a placename (cf. Psalm 42:6, which he miscites as 42:7), or it might be the name of a ship, in which case the people must be the crew and Bodbaal must be the captain; the rest of the papyrus is a list of goods possibly carried by the ship. It's a bit tenuous, admittedly.
Looking at the the two main English-language Phoenician-Punic dictionaries there's no definitive statement.
Tomback's A Comparative Semitic Lexicon of the Phoenician and Punic Languages suggests RB ʾN(Y) "master of the fleet/ship/ships" cf. Hebrew רַב אֳנִי raḇ ʾŏnî "master of the fleet/ships". Citing the inscription: RB[ ] ʾN[Y] HLK[ ] QR[ ] which he translates as "the captain (?) of the fleet (?) travelling (?) to QR (?)" (Pu. Carthage: Slouszch p. 244, ins. #280, line 3). He doesn't explicitly list it as a lemma though.
Krahmalkov's Phoenician-Punic Dictionary (which is occasionally somewhat idiosyncratic, and occasionally untenable, in its readings) doesn't list any specific example, or words for fleets, navies, or naval ships, but gives several definitions of RB: e.g. Master, Leader, Teacher, General (especially if RB MḤNT "master of the army"), Chief, Head, Governor, or Senior.
All in all, something based on RB seems likely, with RB ʾN(Y) being a plausible option, although it may mean something more like "admiral" instead. Seeing as Hebrew also has a singulative אֳנִיָּה ʾŏniyyâ "ship", so a form like RB ʾN(Y)T may be more plausible for the captain of a single ship.
Alternatively ḤBL "sailor" (cf. חובל ḥōḇēl) could be used as the second part. As in Hebrew רב חובל raḇ ḥōḇēl "captain, lit. chief sailor".
Of course, these suggestions are unvocalised. This is because the vast majority of our Phoenician-Punic inscriptions that can be clearly interpreted are in unvocalised Phoenician Script and also lack much in the way of Matres Lectionis. By comparing Greek and Latin transcriptions of Phoenician-Punic to the corresponding Hebrew cognates (Hebrew being the closest well-understood relative of Phoenician-Punic, even if the earliest stage which we have a reliable phonology of is Tiberian Hebrew of the Late 1st Millennium CE), we can make some educated guesses however.
RB was probably something like /ro:b/ in the absolute state, but may have been /rab/ in the construct state as here. In Latin Script these would have been transcribed <rob> and <rab> respectively. In the construct state as here, it's possible the vowel may have been reduced giving /rɨb/ in later Punic which would be transcribed <ryb>, in this case the entire phrase would likely be written as a single word, rather than as two separate words.
ʾN(Y) would probably have been something like /ʔoni:/ in Phoenician, and /ɨni:/ in later Punic. In Latin Script these would have been transcribed <oni> and <yni> respectively.
ʾN(Y)T would probably have been something like /ʔoni:t/, or /ʔonij:o:t/ in Phoenician and /ɨni:t/, or /ʔɨnij:o:/ in later Punic. In Latin Script these would have been transcribed <onit>, <oniiot>, <ynit>, and <yniio> respectively.
ḤBL would probably have been something like /ħu:be:l/ in Phoenician or /(h)i:be:l/, /(h)y:be:l/ in later Punic/ In Latin Script these would have been transcribed <hubel>, <(h)ibel>, or <(h)ybel> respectively (with the latest Punic most likely to lose the h).
Looking a little further afield, Arabic also uses a form of the root R-B-B, رُبَّان rubbān. The expected cognate of this would be something like /rib:u:n/ and would have been transcribed something like <ribbun>, but there is no particular reason to think this formation would be used in this way in Phoenician or Punic.
So my suggestions, in rough order or plausibility by my judgement:
RB: /ro:b/ - <ro:b>RB ḤBL: /rab ħu:be:l/, /rɨb y:be:l/ - <rab hubel>, <rybybel>RB ʾNT: /rab ʔoni:t/, /rɨb ɨni:t/ - <rab onit>, <rybynit>RB ʾNY: /rab ʔoni:/, /rɨb ɨni:/ - <rab oni>, <rybyni>