Wausau pilot. [volume] (Wausau, Wis.) 1896-1940, 1900-11-27
THE GROUND SEA
Peculiar Condition of the Ocean, Which
Wrecks Vessels in Calm.

Peculiar Condition of the Ocean, Which
Wrecks Vessels in q Calm.
Many visitors to the coast at this
time of the year are sorely puzzled
when a boatman either refuses to put
of from shore. or most to go far from
land, on a day when there is no sign
of an approaching storm, and the wa
ter is only moved by a long and gently
rolling swell. Argument is OF 40 avail,
and if the old salt is pushed for
reason he will only reply with some
cryptOgramic remark about the
ground sea-" the questioner retiring
more bewildered than before.
1t is hard to understand how sucn
gentle swell can presage danger, but to
experienced eyes it gives a warning
that must be needed. All along the
west coast of Scotland. uncounted
tales are told of ships which on per-
fectly calm day have been within
few hours first caught by gentle roll
of water and finally thrown on rock
bound shore by the dreaded ground
sea-"
To understand this curious marine
phenomenon it must be borne in mind
that out on the Atlantic waves are
often formed to height of forty feet.
Driven before a heavy gale, these adj
vance at rate of from thirty to forty
miles an hour. Travelling at SUCH
rate they soon get out of the wind
swept area, but even though, for them,
the storm is past, they still roll in fury
their undulations often being felt five
hundred miles from the point Of their
creation.
In the region of the storms these
waves are fierce, breaking pillows, but
as they get further away, they settle
down into long rolling ridges, which
travel onward in long, unbroken lines.
perfectly parallel with each other. Out
on the open sea these ridges often
stretch out for distance of over thirty
miles, and as they travel in three, each
successive wave being larger than its
predecessor, the sight is an imposing
one. The further they progress the
smaller they become in height, but this
is compensated for by the fact that
their motion is communicated to the
mass of water below until the roll can
be detected fully fifty feet under the
surface. This gives them the name of
ground sea-"
In this popularity their danger lies,
for when a becalmed ship is caught
In them her draught the resisting pow
er that enables her to ride out storm,
becomes the fulcrum which the liquid
mass uses to hurl her onward to de-
struction. On a calm day any sailing
craft caught in the ground sea" near
a rocky shore is as good as lost unless
wind can spring UP and enable her to
beat out to sea. Many a ship has met
this fate. The reason many more do
not get lost is due to the gentSe swell
that so deceives a landsman and warns
the sailor.
AS the ground sea" advances it
pushes certain amount of water be-
fore it. This also forms into ridges,
like its pursuer, but of less height and
approximately no depth. The false
sea-" as it is called, is little more
than a rolling swell, but it gives a
warning of from twenty minutes to
two hours duration, enabling ship
either to run into port, get out to sea,
or securely anchor; while at the sea-
side resorts the boatmen run close in
shore. to the surprise Of the "trippers.
When it is remembered that wave
twenty feet high, which is often at
tanned by tne ground sea- strikes
with a force of one ton to the square
inch. the necessity for caution will be
recognized.
All waves that come in parallel rid
ges, however, are not dangerous, as
| there is wind billow'' that is closely
allied to lie ground sea" in appear
ance "Wind pillows" are due to a
| heavy wind blowing but a few miles
| off the land. but as they have but a
comparatively short distance to travel
! they have no depth. Consequently
| even rowing boat is perfectly safe or
! them if properly handled.