Ship Handling Flashcards

The pivot point of a vessel moving ahead at sea is located approximately:

Answer: One-quarter to one-third of the ship's length from the bow

When moving ahead, the pivot point is located approximately 1/4 to 1/3 of the ship's length from the bow, causing the stern to swing wider than the bow.

A vessel is making a port turn in a strong cross-current setting to starboard. What correction should the officer of the watch apply?

Answer: Head the bow further to port to arrive on the intended track

To compensate for a current setting the vessel to starboard, the helmsman must head further to port (upwind/upcurrent) so the resultant track is the intended one.

What is 'squat' as it applies to ship handling?

Answer: The sinkage and trim change caused by vessel speed in shallow water

Squat is the hydrodynamic sinkage and change in trim that occurs when a vessel moves through shallow water, reducing available underkeel clearance.

When anchoring in an emergency, the 'crash stop' maneuver is used. What is the risk associated with this action?

Answer: The anchor chain may part under excessive strain

In a crash stop or emergency anchoring, the sudden loading on the anchor chain when the ship is moving can exceed the chain's breaking strength.

When a vessel is underway in ice, the officer of the watch should prioritize:

Answer: Constant vigilance and reduced speed with frequent reassessment

Ice navigation demands slow speed, continuous monitoring of ice conditions, and readiness to alter course or stop as conditions change rapidly.

What is the effect of a following sea on vessel maneuverability?

Answer: It reduces rudder effectiveness and can cause broaching or yawing

A following sea can cause the vessel to yaw uncontrollably (broach) as wave action alternately accelerates and decelerates the ship, reducing rudder authority.

The term 'underkeel clearance' is critical when navigating in shallow water because:

Answer: Insufficient clearance can cause grounding due to squat and wave action

Adequate underkeel clearance must account for squat, wave action, and tidal range to prevent the keel from striking the bottom.