Sunrise

Sunrise, Claude-Joseph Vernet, 1759, Oil on canvas, 38-1/2 x 53 in.

While there is a great deal happening in this painting, it doesn't feel busy or frantic. The overwhelming impression is of sky.

The sky takes up more than half of the canvas, edging from angry, black, roiling storm clouds in the foreground, to the wispy, haziness of the clouds half obscuring the sunrise. Much of what isn't sky, is sea.
All human activity is restricted to the immediate shore.

This fisherman is, I think, in the classic mode of fisherman as loafer. If this painting depicted life along the water in 20th century Florida, he'd be fishing off a a bridge on the coastal highway. Fishing often serves the appearance of doing something while doing nothing, so perhaps he's simply avoiding going home to his wife, and her long list of chores.

These folks think so too. They appear to be pointing at him and laughing at his expense. Or perhaps at his wife's?
These ladies appear to be bargaining for the day's catch. Housewives looking for fresh fish for dinner? Maybe one of them is wife to our loafing fisherman, and that's why the second group is pointing and laughing: He's so bad a fisherman his wife has to buy fish.

These enterprising sorts are heading out. The baskets that their mules are bearing appear to be empty. Does this indicate success at commerce, or failure at fishing?

Several men gather around a cooking fire, while behind them still others pull in their nets and their catch.

This painting belongs to the period of Vernet's career after his return to France from Italy. At this time, by royal command he painted a series depicting the ports of France, so the setting is likely French. Assuming that to be true, and taking into account the title, this must then depict one of the many ports on the Mediterranean. The fortification in the middle ground appears to be a Martello tower. If the depiction here could be matched to a surviving martello,  or to a similar contemporary depiction or description, it'd be possible to nominate a specific location. 
One interesting tangent: In the Arthur Conan Doyle story The Greek Interpreter, Sherlock Holmes states that his grandmother was the sister of Vernet, the French artist. Based on the dates, it is likely he was referring to Horace Vernet, Jospeh-Claude's grandson.