I managed to find many different dubs of Song of the Sea and it appears there are loads of different dubs, and a lot of them do dub over Dúlamán!
Next time I might do Saoirse's song.
Sinhala: • Song of the Sea: Dúlam...
Galician: • Song of the Sea (A can...
0:00 English
0:51 Portuguese (Brazil)
1:43 Spanish (Spain)
2:34 Czech
3:26 Dutch
4:15 French
5:07 Irish
5:58 Japanese
6:49 Korean
7:40 Lithuanian (Voiceover, English song)
8:35 Polish
9:27 Portuguese (Portugal)
10:17 Russian
11:09 Russian (Voiceover, AVO Y. Serbin, English song)
11:58 Russian (Voiceover, MVO CatBug TV, English song)
12:50 Ukrainian (Voiceover, English song)
13:41 Valencian
The following dubs I found don't have this song dubbed and thus aren't featured:
Catalan
Georgian (Voiceover, despite being a voiceover of the English dub, the song wasn't translated)
German
Italian
Mandarin
Persian (it was cut -_-)
Spanish (Latin America, Universal)
Thai
Turkish
Versions that aren't found in their entirety:
Albanian (since the dub is from Jess Discographic, the songs very well might not be dubbed)
Bengali
Breton
Danish
Hungarian
Kyrgyz
Mizo (very likely illegal dub and might not have the songs dubbed)
Norwegian
Scottish Gaelic
Spanish (Latin America, Waira)
Swedish
Welsh