Complex sentence: On 22 June 1805, in the battle of Cape Finisterre the quartermasters of "Indomptable" spotted the British fleet under Sir Robert Calder, after a violent artillery exchange, the fleets were separated in the fog.
Split into simpler sentences: On 22 June 1805, in the battle of Cape Finisterre the quartermasters of "Indomptable" spotted the British fleet under Sir Robert Calder. After a violent artillery exchange, the fleets became separated in the fog.