Well, in my opinion it is both syntactically and semantically incorrect. Semantically, it would indicate that you actually live in the sea (or potentially in a cave on a rocky coastline). I know this might be a somewhat strange thing (few people if any would actually interpret the sentence this way), but it doesn't change the fact that changing a preposition also changes the semantical meaning of a sentence. In English, use of prepositions is rather complex/strange as we would say e.g. "Jump in(to) my car!", but "Jump on the bus/train!"
That's a good explanation (standing on a bus, but not in a car) - thanks! However, prepositions are tough (in any language), and it's not really easy to pick them correctly in all situations...which is demonstrated by Duo here, saying "She lives IN the west coast". In English, you would e.g. say "she's going to school" not only for the daily walk to the school, but also to describe what is her main occupation. In Norwegian, which is my mother tongue, we would say "på" (usually translating to English 'on' or 'at') for the exact same sentence, which literally indicates that she's going on top of the school building. On the other hand, it wouldn't be interchangeable with the daily walk to school, for which we would use "til" in Norwegian, translating to English "to".
Personally, I sometimes have trouble deciding whether to use "towards" or "against" in English, and also I observe many times that non-natives struggle with "on" vs. "onto" or "upon" (sometimes subtle and not really wrong to skip the 'up' part anyway). For a non-native speaker, it's not always intuitive e.g. that English uses "dependent on" but "independent of" (most languages use the same prep. for both) etc. :-)
The funny thing is that English is the only language I know that does NOT have two different words for this, so it's a bit tricky to translate the difference into English... :-) Examples in other languages:
- 'morar' = German 'wohnen', Norwegian 'bo', Russian 'останавливаться', closest in English maybe 'inhabit' (the place where you have your housing)
- 'viver' = German 'leben', Norwegian 'leve', Russian 'жить', English 'live' in the sence of living your life