Proto-Maritime is reconstructed as having twenty phonemes. It was characterised by three points of vowel articulation, a lack of contrastive voice and the prominence of velar, uvular and glottal sounds. Syllables were simple or moderately complex.
The standard model of PM phonology has stood the test of time, but some uncertainties remain. The language was unwritten. It is believed that there were two dialects, one spoken in what is now Kuna, one in what is now Tepi. Little is known about them, however.
PM had six monophthongs, three short and three long. Long vowels are written double in this transcription.
The International Phonetic Alphabet (IPA) is used here to indicate typical values. No doubt the sound of each vowel varied widely in practice, but few of the details of vowel variation are known.
Close vowels were lowered to close-mid position when adjacent to uvular q or nq. So i would then be pronounced /e/ and u would become /o/.
The central vowel /a/ became a back vowel /ɑ/ when adjacent to q or nq.
All short vowels were somewhat centralised when unstressed in closed syllables. In those positions, they became /ɐ, ɪ, ʊ/ respectively.
The combination of any short monophthong with a reduced i or u was a valid diphthong in PM. A always kept its full sound. At this stage, it is not possible to tell which vowel reduced in the diphthongs iu and ui.
The language does not appear to have possessed any triphthongs.
PM had a set of fourteen consonants. The set was an even mixture of stops, fricatives and sonorants.
Unlike in English, stops were never aspirated and R was always trilled.
Any consonant could be geminated, apart from y, and w. Geminates are written double in this transcription: kk, etc. The trigraphs ngg and nqq represents the geminate /ŋŋ/ and /ɴɴ/ respectively.
Velar consonants became uvular before uvulars. This is reflected in the transcription, except across word boundaries. For example, k+q became qq.
Conversely, uvular consonants became velar before velars: q+k became kk, and so on.
Labial and alveolar consonants were deleted before uvulars. For example, t+q became q.
Nasals were homorganic with the following consonant.
X was in free variation between velar and uvular positions. Hence its transcription above as /x~χ/. The sounds are similar, though the uvular variety is harsher and more salient.
L became /ʟ/ in syllable coda position.
Only the following syllable types were permitted in Proto-Maritime:
(C)V(C), (C)V:(C), (C)VV(C)
Any consonant could appear in onset position. Any could be found as a coda, except for y and w.
Syllables were classed as light: (C)V; heavy (C)VC, (C)V:, (C)VV or superheavy: (C)V:C, (C)VVC.
Stress normally fell on the penultimate syllable. However, if the final syllable was heavier, it took the stress instead. Secondary stress occurred on every alternate syllable before the one with primary stress.