query: # people born at sea
  SELECT DISTINCT ?person ?personLabel ?placeLabel ?dob WHERE {
   ?person wdt:P19 ?place.
   { ?place wdt:P31/wdt:P279* wd:Q165. } UNION { ?place wdt:P31/wdt:P279* wd:Q1229765. }
   OPTIONAL { ?person wdt:P569 ?dob. }
   SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
  }
  ORDER BY ?dob ?placeLabel