▁T oth ▁( a ▁compet itive ▁sw immer ▁who ▁would ▁also ▁successfully ▁sw im ▁the ▁distance ▁in ▁ 1 9 2 3 ), ▁setting ▁an ▁American ▁record ▁of ▁continu ously ▁sw imming ▁for ▁ 2 0 ▁hours ▁and ▁ 2 8 ▁minutes ▁while ▁attempting ▁to ▁sw im ▁from ▁Prov inc et own , ▁Massachusetts ▁to ▁N ant uck et . ▁He ▁made ▁two ▁more ▁attempts ▁at ▁the ▁channel ▁crossing ▁in ▁ 1 9 2 0 , ▁his ▁best ▁effort ▁leaving ▁him ▁ 1 . 5 ▁miles ▁from ▁the ▁French ▁coast ▁before ▁unf avor able ▁t ides ▁forced ▁him ▁to ▁give ▁up . ▁In ▁a ▁ 1 9 2 1 ▁attempt , ▁he ▁was ▁forced ▁to ▁quit ▁while ▁within ▁five ▁miles ▁of ▁France ▁after ▁sw imming ▁for ▁ 1 9 ▁hours ▁and ▁ 5 ▁minutes . ▁S ull ivan ▁had ▁sought ▁to ▁make ▁an ▁attempt ▁at ▁the ▁crossing ▁during ▁the ▁ 1 9 2 2 ▁sw imming ▁season , ▁but ▁poor ▁weather ▁conditions ▁led ▁him ▁not ▁to ▁make ▁another ▁try . ▁ ▁S ull ivan ▁was ▁successful ▁in ▁his ▁sevent h ▁attempt , ▁in ▁a ▁calm ▁sea ▁and ▁a ▁water ▁temperature ▁of ▁ 6 2 ▁degrees . ▁He ▁entered ▁the ▁water ▁in ▁D over ▁at ▁ 4 : 2 0 ▁on ▁Sunday ▁afternoon , ▁August ▁ 5 , ▁and ▁began ▁his ▁sw im . ▁Though ▁the ▁straight - line ▁distance ▁is ▁ 2 2 . 5 ▁miles , ▁cho ppy ▁waters ▁and ▁cap r icious ▁t ides ▁forced ▁him ▁to ▁sw im ▁an ▁estimated