While operating your boat there will be times when you will need to enter a port in rough and challenging conditions.
Although certain inlets and rivers have extreme conditions much more
often than others, learning how rough weather affects the various
harbors and entrances throughout your local area is necessary to operate
Knowing as much information as possible prior to entering a
harbor, inlet, or river in rough weather will help guard against
potential dangers or impending problems. In these cases local knowledge
can make the difference between a safe passage or getting you and your
crew in trouble. If you are operating in an area which is new or
unfamiliar to you “local knowledge” can also be gained through the use
of cruising guides or Coast Pilots found in many ship stores or online.
Here are a few things you should be aware of before entering any of
- Watch where waves break. Know how far out into the channel, whether
near jetties or shoals, or directly across the entrance the waves break.
- Pay close attention to how the entrance affects wave patterns. An
entrance that has jetties may push waves back across an entrance where
they combine with the original waves.
- Some entrances have an outer bar that breaks, and then additional
breaks farther in. Others are susceptible to a large, heaving motion
that creates a heavy surge as it hits rocks or structures.
- Know where the channel actually is. If shoaling has occurred, room to maneuver may be significantly reduced.
- Know the actual depths of the water. Account for any difference
between actual and charted depth due to water stage, height of tide,
recent rainfall, or atmospheric pressure effects.
When entering a harbor, inlet, or river you will need to pay
special attention to the direction of the current and seas. The most
challenging condition you can encounter is when the current opposes the
seas when operating near an entrance. In this case the current will have
the effect of shortening the wavelength, and increasing the wave
height. This makes waves much more unstable and closer together.
heading into the oncoming seas, you will find that the current is coming
from behind your vessel thus pushing your boat into the seas at a
relatively higher speed. You can reduce this effect (which will also
give more time to react between waves) by slowing your vessel, although
the current is coming from behind you will still need to keep enough
headway to ensure effective steering.
When transiting an
entrance, you will find that maneuvering room is often very limited. The
only safe water may be found in the area that you just left. Be ready
to back down and avoid the breaking crest of a wave. This situation can
become critical in following seas with a head current. The waves will
overtake your vessel at a higher rate and will break more often. The
current will reduce your boat’s speed over the ground (SOG) which will
expose your vessel to more waves. In this condition it is important to
remain calm and not panic.
Remember that with all
following seas, you need to stay on the back of the wave ahead. As these
waves become unstable they tend to break more quickly, use extra
caution to ensure that you do not go over the crest of the wave ahead.
Concentrate both on the crest in front of you and the waves behind. You
must keep a hand on the throttle and adjust your power continuously.