As nouns the difference between seaweed and tideline

is that seaweed is any of numerous marine plants and algae, such as a kelp while tideline is a line of floating debris, seaweed etc that marks the boundary between two surface currents.

As nouns the difference between boundary and tideline

is that boundary is the dividing line or location between two areas while tideline is a line of floating debris, seaweed etc that marks the boundary between two surface currents.

As nouns the difference between surface and tideline

is that surface is the overside or up-side of a flat object such as a table, or of a liquid while tideline is a line of floating debris, seaweed etc. that marks the boundary between two surface currents.

As a verb surface

is to provide something with a surface.

As nouns the difference between current and tideline

is that current is the part of a fluid that moves continuously in a certain direction while tideline is a line of floating debris, seaweed etc that marks the boundary between two surface currents.

As an adjective current

is existing or occurring at the moment.

As adjectives the difference between relentless and unalleviated

is that relentless is unrelenting or unyielding in severity while unalleviated is relentless.

As a noun open

is .

As an adjective sideless is

lacking a side; open at the sides.

As a verb marine

is .

As a noun spadefish is

(zoology) any of several marine fish of the family .

As a proper noun fish

is .

As a noun spadefish is

(zoology) any of several marine fish of the family .

As nouns the difference between line and tideline

is that line is a path through two or more points (compare ‘segment’); a continuous mark, including as made by a pen; any path, curved or straight while tideline is a line of floating debris, seaweed etc. that marks the boundary between two surface currents.

As a verb line

is to place (objects) into a line (usually used with "up"); to form into a line; to align.

As nouns the difference between debris and tideline

is that debris is while tideline is a line of floating debris, seaweed etc that marks the boundary between two surface currents.