Albert Julius Olsson

Albert Julius Olsson (1864—1942) was born in London, the son of a Swedish father and English mother, the 'artist was within him' and he was wholly self-taught. A daring yachtsman, some of his marine scenes look back at the coastline from onboard ship. His work was in the late impressionist style of Henry Moore.
From the examples of his paintings I can find on Google image search it seems Olsson was particularly fond of painting the sea in moonlight.

Winslow Homer - Fishing

Kissing the Moon

Saco Bay

The Herring Net

Fog Warning
The last painting, Shark Fishing, 1885, is a watercolor.
Homer's work as an illustrator seems to have given him a wonderful eye for image-making. He makes strong, iconic images that reproduce well, and would not be out-competed by text.
This is due to: interesting viewpoints, simplicity of design, zooming in to the subject, strong tonal contrasts, and energetic lines.

Maritime Time

Charles Vickery, Racing Clippers 'Ariel' and 'Taeping', 30 x 40 inches.
Geoff Hunt
Harvey T. Dunn, For a Space of Minutes, 1915
Unknown, Rogue Wave, Queen Mary
Gordon Grant

Polly Seip

Polly Seip is a contemporary painter based in CT, in the US.
I love the use of wide format in these works, and the exploration of the changing effects of light on the sea.
Here's a link to her studio blog: pollyseipfineart.blogspot.com

Here's another example of a wide format composition, by the British painter Frederick William Hayes. This is from the collection of the Victoria and Albert Museum.

Criccieth, Wales, late 19th century.

People on the Beach

Elihu Veder, Greek Girls Bathing.
Frederik Hendrik Kaemmerer, A Beach Stroll.
Gabriel-Charles Deneux, Les peintres de retour du Mont Saint-Michel.
Frederick A Bridgman, Seaweed Gatherers.
Thomas Cooper Gotch, The Sand Bar.
.

These painters have used figures to great effect in enlivening their beachscapes. Rods and pitchforks carried by the figures add diagonal linear elements. Clothing is also an opportunity to introduce some red or dark accents to contrast with the neutral coloured surf and sand.

Horses

Rowland Wheelwright, Summertime, 47 x 71 inches
Rowland Wheelwright, The Enchanted Shore

Lucy Kemp-Welch, Horses Bathing in the Sea, 1900

Lucy Kemp-Welch, Sea Horses

The Bridgewater Sea Piece

Possibly my favourite marine painting, J.M.W. Turner's Dutch Boats in a Gale (the Bridgewater Sea Piece), 1801, was painted as a pendant (companion piece hanging below) to a similar scene by Willem van de Velde for the 3rd Duke of Bridgewater. See below:

Turner's application of oil paint became increasing transparent and washy as he matured, and his oils began to look more and more like watercolours. This fluidity allowed him to create wonderfully subtle and luminous atmospheric effects.

The Fighting Temeraire, 1839