This painting is an anonymous copy of the 1773 painting by Vernet, which hangs in the Mauritshuis art museum in The Hague, Netherlands. The work's anonymity was common for the time, as aspiring artists often copied the painters they admired in order to study their technique. Vernet, one of the most celebrated French painters in his lifetime (1714-1789) and beyond, was known for his studies of dramatic skies over land and sea, and was often copied in both paintings and intaglio prints.
This unsigned oil is on an oak panel, the verso of which has been counter-mounted with linen.
A Personal Speculation: It may well be a painting by Vernet's teacher, French painter Adrien Manglard (1695-1760) who initiated Vernet into seascape painting and himself painted a number of dramatic shipwrecks and rescues along the coasts of the Mediterranean. Manglard had moved to Rome around 1722 and met Vernet when he left France. Both Manglard and Vernet had studied with the Italian marine painter Bernardino Fiergioni (1674-1738) but both appear to have exceeded their teacher's talents.
Having now expounded on this I have nothing to back up my speculation, just an interesting venture down the rabbithole of the internet. A ride worth taking.