This slow growing hybrid of H. 'Blue Moon' was registered in 1994 by Charles Seaver of Delaware. It forms a large size hosta about 21 inches tall and 60 inches wide with heavily corrugated, moderately cupped, shiny foliage. Dense clusters of very pale lavender flowers bloom in late July followed by viable seeds.

According to The Hostapedia by Mark Zilis (2009), "Maturity brought out the intense corrugation, cupping, good blue color, and plastic like substance that were not evident at an earlier age...Every hosta collector should own 'Deep Blue Sea."

The New Encyclopedia of Hostas by Diana Grenfell (2009) states: "Leaves unfurl light gteen soon becoming a superb blue and keeping their color for most of the summer...Exaggeratedly rugose to seersuckered toward central midrib, almost distorting the symmetry of the leaf. Lobes are sometimes twisted behind the petioles."

A Photo Essay article by Steve Chamberlain in The Hostta Journal (2010 Vol. 41 No. 1) makes comments about H. 'Deep Blue Sea', "Charles Seaver registered this 'Blue Moon' seedling in 1994. My plant was a gift from Charlie at the Hostas in Focus Festival in 1997. Early in the season this plant is an intense blue with extreme corrugation. By the time it blooms later in the season, the wax has washed off and the leaves are dark green and very shiny."