Underwater Marine

Four Leaping Sailfish and Halfbeak, 24 x 43 inches.
Bonefish, Four Bones up with the Tide.

Another sub-genre of marine art is the underwater marine.  

The American artist and illustrator Stanley Meltzoff (1917-2006) was a master of this type of scene, skillfully combining wild-life painting and underwater seascape. He was probably the originator of this genre.

stanleymeltzoff.com

Women On Deck

Emanuel Phillips Fox, Australian, The Ferry.
Julius LeBlanc Stewart, American, On the Yacht Namouna, Venice. 
Raoul Du Gardier, White Calm, Telfair Museum.

This is a kind of sub-genre of nautical painting that seems to have been popular in the late 19th century and early 20th century. It had plenty of scope for interesting compositions combining figures, cloth, linear elements (both curving and straight) and seascape.

A Peaceful Christmas

James Tissot, Christ Asleep During the Storm
Not sure of the medium here. Could be gouache or watercolor, or a combination.

Tissot (French, 1836–1902) is best known for his depictions of fashionable Parisian women (as in the centre image: HMAS Culcutta, painted in 1877, which looks like an oil), but in his later years he turned to illustrating scenes from the Old and New Testament.

The Hull of a Battle Ship (bottom image) definitely looks like an oil.

Decisive Brushstrokes

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These plein air studies, by David Simons, work well because the artist has chosen subjects which are simple yet contain interesting shapes and relationships.

Good plein air painting is characterised by decisive brushstrokes - as few as possible to convey the scene - varied to produce interesting patterns. Brushstrokes should follow the form of an object.

Both studies are 16 x 20 inches.

Sothebys Auction - American paintings

Top to bottom: William Trost Richards, Frederick Judd Waugh

Bird's Eye View

The Golden Rose, oil on paper on panel, 2007, 36 x 3ft 12 inches

Farseekers - Journey, oil on paper mounted on masonite, 27 x 32 inches

These illustrations by the New York based artist, Donato Giancola, are striking in their use of aerial perspectives. Though the works are quite large, Giancola has chosen paper mounted on panel for his support. 

When working in fine detail, paper is a good option as it provides a smooth surface unobtainable with canvas without lots of priming, sanded between coats. Paper, however, needs to be mounted on a panel or canvas support, with an archival glue, to prevent buckling and damage. 

Artist's website