Your examiner has already asked you how to tune sea and rain clutter controls in practice on watch. This time they ask instead: "Electronically, what is each control actually doing to the received signal?"

A. The anti-clutter SEA control (STC — Sensitivity Time Control, sometimes called swept gain) reduces the RECEIVER'S GAIN for a short period immediately after each pulse is transmitted, progressively restoring full gain as range increases — because sea clutter returns are strongest at short range (close to own ship) and weaken with distance, this suppresses the many small, strong, random echoes from wave crests near the ship without suppressing genuine target echoes at greater range, where gain has been restored to normal. The anti-clutter RAIN control (FTC — Fast Time Constant) works differently: it differentiates the received signal based on PULSE DURATION, passing only the leading edge of a return and suppressing the "smeared," longer-duration returns typical of rain and snow, while a genuine, short, well-defined target echo largely passes through unaffected. FTC therefore works on the SHAPE of the return over time, not on its range from own ship.

B. STC and FTC are two names for exactly the same electronic process — both simply turn down the overall gain of the receiver equally at all ranges, with no difference in how they treat sea versus rain clutter.

C. STC works by differentiating on pulse duration (suppressing long-duration returns), and FTC works by reducing gain at short range — the reverse of their actual functions.

D. Both STC and FTC operate entirely on the transmitter, reducing transmitted power rather than processing the received echo in any way.

A. Nothing — a test lift can proceed immediately after repairs

B. Testing should wait until cargo operations begin

C. The area within the grab's swing radius should be cleared of personnel before the lift

D. Only the crane operator needs to be aware the lift is happening

A. Who must remain clear of the exclusion zone while the lift takes place

B. The lunch schedule for the deck team

C. Only the weather forecast for the next watch

D. The cargo manifest for the next port