Rubuta ci gaba ga wannan sakin layi - Gosselin ya shiga Royal Navy a ranar 2 ga Agusta 1778 a matsayin mai bin Kyaftin Philip Boteler a cikin sabon jirgin ruwa. Daga bisani sai ya canja tare da Kyaftin Boteler zuwa jirgin ruwa a watan Yuni 1779. A ranar 16 ga watan Agusta "Ardent" ya kama shi ta hanyar haɗin gwiwar Faransa da Mutanen Espanya kusa da Portsmouth. Gosselin ya shafe watanni uku a matsayin fursunonin yaƙi a Alençon. Bayan da aka sake shi ya shiga jirgin-na-layi, jirgin tutar Rear-Admiral Sir Samuel Hood, a ranar 11 ga Oktoba, 1780. A kan "Barfleur" Gosselin ya shiga cikin manyan ayyukan juyin juya halin Amurka a matsayin wani ɓangare na rundunar Admiral Sir George Rodney, ciki har da yakin Fort Royal
, Yaƙin Chesapeake, da Yaƙin Saint Kitts. Bayan wannan yaƙin Gosselin ya koma jirgin ruwa wanda ɗan'uwan Rear-Admiral Hood ya umurce shi, Kyaftin Alexander Hood. A cikin "Champion" Gosselin ya shiga cikin yakin Delaware Bay da yakin Saintes, inda babban jami'in Faransa François Joseph Paul de Grasse ya mika wuya. Gosselin ya kuma kasance a yakin da aka yi a Mona Passage inda rundunar soja a karkashin Rear-Admiral Hood ta kama wani jirgin Faransa mai tserewa, tare da "Champion" wanda ya kama wani jirgin ruwa na Faransa. A watan Yunin 1782 Gosselin ya canja tare da Kyaftin Hood zuwa jirgin ruwa mai suna HMS "Aimable", yana aiki a cikinta har sai juyin juya halin Amurka ya ƙare tare da Yarjejeniyar Paris a 1783. Ya koma gida a ranar 26 ga Yuni 1783.