Although many recreational boats may or may not require a radar (mainly depends on the needs), it is required for big vessels, yachts, container ships, etc. So, standing next to a big radar on a boat poses any threat to human health? Are boat radars dangerous? Can a boat radar hurt you while boating? Let’s see in a simplistic way.
Boat radars are not dangerous; they don’t pose any threat to humans because they emit non-ionizing radiation, which doesn’t penetrate the human body. Radiofrequency fields above 10 GHz at power densities over 1000 W/m^2 are a risk; but, those numbers are “far away” for a normal radar most boats use.
Unlike X-rays and nuclear radiation, marine radars emit non-ionizing radiation, which will not penetrate the human body. Still, they can cause a minor heating sensation on the skin’s surface and eyes (cornea). Ionizing radiation can cause chemical changes in cells and damage DNA, but non-ionizing won’t do that.
Throughout the post, you will hear some “technical” terms (like EMF, RF, SAR, etc.) and “values” (like GHz, W/m2, μW/cm2). You need not worry about all those terms and words because we explained them in very simple terms as possible.
Skip this section if you already know the basics of radar working and their ranges.
Radars send electromagnetic fields (EMF) in the form of short pulses (not continuous) in a narrow beam, and these pulses will reflect back when they hit any object (like other boats, landmasses, or any), generating a picture of the boat’s surroundings on a display screen.
Depending on the model, the radar’s range varies from miles to hundreds of miles or more. Meaning it will splash electromagnetic fields for hundreds of miles or more. Marine radar systems operate in the high radio frequency (RF) from around 20kHz to around 300GHz and microwave range.
Marine radars are either X-band (frequency range of 8.0 GHz – 12.0 GHz) or S-band (frequency range of 2.0 GHz – 4.0 GHz). Even the radars in the big container ships won’t exceed 12GHz. On the other hand, recreational boat radars will be much smaller compared to ships.
Exposure to radiofrequency (RF) fields from 1MHz to 10GHz will cause a heating sensation on the skin’s surface and eyes (cornea), but this is a very minute (little) threat. Above 10GHz, power density is the measured quantity (measured in W/m^2) rather than RF; the higher the power density, the higher the risk.
Exposure to RF fields above 10 GHz at power densities over 1000 W/m^2 produces adverse health effects, such as eye cataracts and skin burns. However, even with the biggest radars used in large container ships, the power density is less than (around) 10 W/m^2, which is very less to produces adverse health effects.
The power density of the radars used in recreational boats will be a lot lesser (than 1 W/m^2), and it won’t affect anything. Ultimately, radars on a boat are not dangerous, and they don’t pose any threat to humans even if you are standing near a big radar on the boat.
Related post – What boats need radars? Check this article to know more about boat radars, and what types of vessels require one.
Check this informational video on how radars work to know more about them in a more illustrative way.
What are the health effects of marine radars?
Although there are no adverse health effects of marine radars on humans, they do pose some minor effects. We will now see them in a detailed way.
Marine radars cause a heating sensation on the skin surface and the eye (cornea). However, these effects are minor. To cause some adverse health effects, you need to expose to RF fields above 10 GHz at power densities over 1000 W/m^2, and those numbers are “far away” for a marine radar.
Ionizing or Nuclear radiation will change a cell’s biological structure because they have enough energy to remove an electron (negative particle) from an atom or molecule, causing it to become ionized. Since radars emit non-ionizing radiation so they won’t cause chemical changes in cells and damage DNA.
Many will remember the word cancer the moment they heard the word radar. Several national and international peer-review groups have concluded that there is no clear evidence that radiofrequency (RF) exposure will shorten humans’ life span or that RF is an inducer or promoter of cancer (source).
It is important to distinguish between perceived and real dangers that radars pose, as well as to understand the motive behind existing international standards and protective measures used today.
World Health Organization
Exposure to RF fields above 10 GHz at power densities over 1000 W/m^2 produces adverse health effects, such as eye cataracts and skin burns. However, even with the biggest radars used by large container ships, the power density is less than (around) 10 W/m^2, which is very less to produce any adverse health effects.
Specific absorption rate (SAR) is a measure of the rate at which energy (radiation) is absorbed per unit mass by a human body when exposed to a radio frequency (RF) electromagnetic field. SAR of at least 4 W/kg is needed to produce known adverse health effects in people exposed to RF fields in this frequency range.
| Device | SAR (W/kg) |
| Cell phone | 1.6 |
| Microwave | 0.05 – 1 |
| Wi-Fi router | 1.6 |
| Radar | <2 |
Those are the average SAR values for different devices, and the SAR values can increase if you move close to the device and decrease if you move away from the device. 4 W/kg is far away for a radar used in recreational boats. So, marine radars don’t pose any adverse health threat to humans.
WHO states, “To date, researchers have not found evidence that multiple exposures to RF fields below threshold levels cause any adverse health effects, including cancer. No accumulation of damage occurs to tissues from repeated low-level RF exposure.” So they are not as dangerous as many people expected them to be.
How often are humans exposed to marine radar (radiation)?
We will now see what are all the possible ways that you could receive radiofrequency (radiation) from a marine radar if you are on a boat.
Humans on the boat will not constantly be exposed to radiation due to radar because radar sends electromagnetic waves in pulses, not continuous. The radar rotates or varies its height by a nodding motion, thus constantly changing the beam’s direction. So, exposure will be less than you think.
Did you know? RF fields can ignite flammable liquids and explosives through the induction of currents. This is a rare occurrence and normally of most concern where there is a large concentration of radars, such as onboard a naval ship where measures are taken to prevent such effects.
World Health Organization
- Electromagnetic waves are “pulses”; they are not continuous. This reduces the average radiation absorbed by humans, though not drastic reduction, but it will reduce somewhat.
- Most marine radars will be rotating and sending electromagnetic fields all the time. Already the radiation is a bit reduced in the form of pulses, and now it will reduce furthermore due to the rotation of the radars continuously.
- Distance between the radar and human is crucial. If you stand 10 meters away from the radar, you will closely get half the radiation of the person standing 5 meters away from the radar.
The radiation level people might be exposed to when they are near a marine radar will depend on those additional factors. Even if there are any disturbances between the radar and you (like walls, objects, persons, etc.), the radiation reduces, and the amount of radiation you might absorb also reduces.
Since marine radars usually operate with a pulsed signal, and it will be rotating all the time, so people are not continuously exposed to radiation even if they are in a fixed position, such as a crane cab or an office adjacent to shipping. However, the marine radars emit non-ionizing radiations, which will not penetrate the human body.
Key takeaways
Marine radars send electromagnetic fields that are non-ionizable, meaning they won’t cause chemical changes in cells and damage DNA, but they can cause a minor heating sensation on the skin’s surface and eyes (cornea). So, marine radars are not dangerous and will not hurt anyone.
Exposure to radiofrequency (RF) fields above 10 GHz at power densities over 1000 W/m^2 produces adverse health effects, such as eye cataracts and skin burns. However, even with the biggest radars used in large container ships, the power density is less than (around) 10 W/m^2, which is very less to produces adverse health effects.
To date, researchers have not found any evidence that multiple exposures to RF fields below threshold levels cause any adverse health effects, including cancer. No accumulation of damage occurs to tissues from repeated low-level RF exposure (source).
To produce any adverse health effect, RF exposure above a threshold level must occur. The known threshold level is the exposure needed to increase tissue temperature by at least 1°C. The very low RF environmental field levels from radar systems cannot cause any significant temperature rise (source).
