Natant

na·tant /ˈneɪtnt/ [neyt-nt]
–adjective
1. swimming; floating.
2. Botany. floating on water, as the leaf of an aquatic plant.

[Origin: 1700–10; < L natant- (s. of natāns), prp. of natāre to swim; see -ant]

—Related forms
na·tant·ly, adverb

Littoral

littoral \LIH-tuh-rul\
adjective:
1. Of, relating to, or on a coastal or shore region, especially a seashore.
noun:
1. A coastal region, especially the zone between the limits of high and low tides.