What to know for Controls, Gain, and Clutter
Adjust common radar controls deliberately and understand the trade-off each control creates.
Gain, sea clutter, rain clutter, tuning, range scale, trails, and display setup. This module is mapped to the published course boundary for Marine Radar Revision and written as an independent revision aid, not official training material.
Key Points
- Too much gain fills the screen; too little hides targets
- Sea clutter controls near-range wave returns
- Rain clutter can also suppress real echoes
- Range scale affects target detail and planning time
Last reviewed: 6 July 2026 by Compass Revision curriculum review
Source notes
Revision checks
Use these checks before moving on. If one feels vague, reread the module and compare it with the linked official source before treating the topic as learned.
Core topic tags: gain, sea clutter, rain clutter, range scale.
Key Points
- Can you explain: Too much gain fills the screen; too little hides targets?
- Can you explain: Sea clutter controls near-range wave returns?
- Can you explain: Rain clutter can also suppress real echoes?
- Can you explain: Range scale affects target detail and planning time?
Source notes
Common mistakes
Most assessment and real-world errors come from misreading the situation, skipping a simple check, or treating a memory aid as a substitute for judgement.
Use this section as a pre-test: if you can explain why each mistake is risky, you are closer to usable knowledge.
Key Points
- Turning clutter controls too high
- Using one range scale only
- Not returning controls after a trial adjustment