Last Updated：2025/11/23
(nautical) The farthest point above the mouth of a river that can be navigated by ships. This term can be somewhat subjective on many streams, as this point may vary greatly with the size of the ship being contemplated for navigation. On others it is quite objective, being caused by a waterfall, dam or lock.
音声機能が動作しない場合はこちらをご確認ください
See correct answer
head of navigation
Edit Histories（0）
Source Word
head of navigation
Noun
(nautical)
The
farthest
point
above
the
mouth
of
a
river
that
can
be
navigated
by
ships.
This
term
can
be
somewhat
subjective
on
many
streams,
as
this
point
may
vary
greatly
with
the
size
of
the
ship
being
contemplated
for
navigation.
On
others
it
is
quite
objective,
being
caused
by
a
waterfall,
dam
or
lock.
Japanese Meaning
河川で船舶が航行可能な上流端、すなわち船の大きさによって変動する可能性があるが、通常は滝、ダム、船渠などによって航行が制限される地点を意味する。
Sense（1）
(nautical)
The
farthest
point
above
the
mouth
of
a
river
that
can
be
navigated
by
ships.
This
term
can
be
somewhat
subjective
on
many
streams,
as
this
point
may
vary
greatly
with
the
size
of
the
ship
being
contemplated
for
navigation.
On
others
it
is
quite
objective,
being
caused
by
a
waterfall,
dam
or
lock.
