Reference / Clear explanations
Questions From the Helm
The short answer should make the next check clearer. Open a question for the distinction that matters, then follow the relevant guide for context.
Is GPS the same as GNSS?
GNSS is the general term for satellite navigation systems. GPS is one constellation within that category. A multi-constellation receiver can use other supported systems, but chart quality and installation still matter.
Why do heading and course over ground disagree?
Heading describes where the bow points; course over ground describes movement across the earth. Wind and current can separate them. At very low speed, course over ground can be unstable; heading sensor errors are another possibility.
Can I navigate using a chartplotter alone?
Do not make one display your only source of navigational confidence. Review appropriate current charts and local information, maintain a lookout and carry an independent method suited to the passage. Shared power and sensors can defeat apparent redundancy.
Why does sonar lose the bottom at speed?
Aerated water across the transducer, mounting position, settings, depth and interference can contribute. Inspect the installation and consult the manufacturer's guidance rather than assuming more transmitter power will solve it.
Does AIS show every nearby boat?
No. Some vessels do not carry AIS, and transmissions can be missed or information can be stale. AIS supplements lookout and other appropriate collision-avoidance information; it does not replace them.
What does a DSC radio need besides an MMSI?
It needs a suitable antenna installation, dependable power, correct configuration and valid position input where supported. Registration, licensing and operator requirements depend on jurisdiction. Follow the equipment manual and local authority guidance.
Can I compare batteries by amp-hours alone?
Not reliably. Voltage, chemistry, usable discharge limits, temperature, condition and current capability matter. Watt-hours provide energy context, but a safe replacement also requires charging and protection compatibility.
Are two helm displays a fully independent backup?
Not if they depend on the same supply, network, antenna or data source. Trace common failure points and choose an independent fallback appropriate to the vessel and passage.
Why does an electric boat's predicted range change?
The estimate depends on available usable energy and expected consumption. Speed, wind, current, loading, hull condition and temperature can change demand. Keep a reserve and reassess the passage when conditions change.