Radar Reflector

I’m looking for a practical way to acquire and mount a radar reflector on sea kayak (or sea kayak paddler). Paddling in Penobscot Bay, ME, it would be useful in the frequent fogs. Any recommendations?

Waste of time and effort

– Last Updated: Aug-18-12 3:32 PM EST –

You are maybe 2 feet above the water in a boat
made of something "other" than metal, maybe 20ft max .
Adding a teensy tiny amount of "reflecting" material
in an enormous gigantic body of water is like
putting a firefly in a glass jar on your bow.
NO ONE will see you on a radar screen.

Generally, sea kayaks 1 mile from a radar
platform are not visible on radar,
whether or not they have reflectors.

You will look like "noise" on the radar screen,
one pixel lit up in an UN-recognizable pattern,
and no one will pay attention to it.


Make securité calls on VHF channel 16
to advise other boating traffic that
a KAYAK crossing is underway, and specify
exact points of crossing.

BE VISIBLE via a flipping/flopping flag
with some SOLAS reflective tape on it

Doesn’t work
Sea Kayaker magazine did a test of this with the USCG some years ago and it was found that, even mounted a couple of feet above the deck, they didn’t work. Your best defense against ships is your good judgment, which includes picking appropriate weather and times to make crossings.

…or a really big sail made out of tinfoil. Would work until a breeze came up.

Hi Charlie,

The emperical evidence shows that you really can’t count on being seen on radar, even with an expensive reflector. (The MASKGI trials found that nothing worked well, but that tinfoil in your hat worked a bit better than the more sophisticated reflectors.)

In addition to the problem of not being radar reflective, you just can’t count on other boats to have radar, or be looking at it. Instead, as kayakers, we need to be more proactive about staying safe in fog. Most importantly, we should just stay out of open water when there’s dense fog. Stay in the shallows, follow the shoreline on those days. And if you are forced to make a crossing, go out of your way to only make crossings that are really really short, and use Securite calls on your VHF, and a loud horn.

Cheers, Nate

'tis true…
since so many ships are automated now, there may or may not be someone monitoring the radar. Many are computer driven and have automated collision avoidance systems (as well as operators who may, or may not, be competent in using those systems). If this is the case, it still may not matter unless the avoidance system was designed to attend to radar profiles below a certain threshold.

In addition, some really large ships are very slow to respond to helm. Even if you were detected, it would likely be too late for the ship to make a meaningful course correction. Visual detection is also a huge issue since you are both really small and hard to see, as demonstrated by this video:




Owwwwie $ 400 bones

– Last Updated: Aug-21-12 2:36 PM EST –

I already have a VHF, a GPS, a Horn and a Compass
- mix in some good rational common sense, I'm good


I'm not sure $400 of technology will fix
the poor judgement of "being in the soup" so severely,
and in a shipping channels, playing sea frogger,
that I need that in my kayak.
Situational awareness, where the lighted buoys are,
known shipping channels, etc is important.

My money would go towards a SPOT unit instead.
It sends a "help" message which the VRB won't.

comment shipping side
Out local kayak club (bay Area Sea Kayakers) had a pair of guys from the vessel Traffic service (the Coast Guard operation that manages the shipping traffic in the SF Bay). Both were ex Navy.

The question came up about visibility to radar, and they emphatically said that kayaks are not visible to radar, even if they try adding some sort of radar reflector. We are just too low on the water.

An aside was then said - there is one radar that could pick us up. The targeting radar for the guns on Navy ships. Not sure we want to be on that one…

Looking at the specs
for the active radar reflector indicates that it’s rage limited to 2.5 miles when elevated 2 meters over the water surface. Even if the spec is accurate and I mounted the device on my head, I don’t think I could get it high enough to produce more than a tiny blip if I were at the top of a swell and the sender was at an opposite depth in a trough. In best conditions, on calm water, I doubt it would make much of an impression.

I have to admit that I’m guessing here, so it may be worth testing and I’d like to think I’d be pleasantly surprised by the result (yeah, I’m a pessimist at heart).


Be careful what you post

You are absolutely 100% wrong about modern shipping. If any crew of any vessel was ever found to not have both a lookout on the bridge wing (Looking listening and indeed smelling for everything and everything) and an officer at the electronics, they would be criminally negligent according to IMO, Transport Canada and US equivalent federal regulator.

Kayaks do not show up on Radar, that is true, but Ships are not completely automated. I’ve worked on them and had my Limited Masters Captains papers in Canada at one point in my life and I can tell you having no watch is very illegal!