Radar mount is not straight on my Cutwater .

[BB marine]

What is the best way to shim the radar so it is laying straight. Also has any one shimmed the radar dome to be pitched down toward the bow. The Cutwater 26 runs with the bow riding high when running 2500 rpm or higher. To get the best performance out of a radar the dome should be transmitting in a level plane . Most dome mounting brackets or plates have a slight angle built into them so that when the boat is in operation the radar is transmitting level to maintain range. When I'm running at my cruise speed with the boat trimmed my dome is listing to the starboard and aiming to the sky. I have a picture in my album of my radar dome mounted. Has any one added a wedge to the factory bracket and what angle wedge did you use.

 

[knotflying]

I would ask the manufacturer to correct the sloped dome. Something does not seem right.

 

[Andrew Custis]

The radar should be mounted flat and close to parallel with the water line. The good thing about these radar units is they have a nice beam that shoot 12.5 degrees above and below the radiating element. if you are running very bow high you might think about loading more weight in the bow or making your tab plates bigger if you are heavy in the stern. Ive noticed cruising on our longer distance trips that if I overload the stern on any of the models the tabs do not become near as effective. Making a weight shift was all the difference in the world. I've not had to use any shims to make the performance better on our boats but it is certainly something that could be done.

Thank you,

 

[JamesTXSD]

One more consideration: when you need radar, it is because of low visibility conditions. Realistically, you should be running at a speed that would allow you to stop the boat in whatever distance you can see. Displacement speed in fog - the bow is not likely to raise as much as high cruise speed.

I have been out in conditions that are very low, doing 5 knots or so... and seeing targets on radar that are moving at 30 knots. Radar may not pick up a floating log... or worse, a deadhead. Running at speed in those conditions, you won't be able to see and avoid debris in the water. It is that configuration/situation where you want your radar to be level.

 

[tlkenyon]

My Garmin radar has a setting that you can change to alter the angle of the radiating element based on the boat attitude. Maybe try that? The selection is in the radar setup menus.

TK

 

[Diatom]

Commenting on an old thread re an old question: should radar be shimmed to account for boat attitude?
I snapped some pics of my old C26 at displacement speed & edge-detected them, then inverted to negatives and attacked them with a protractor & pencil. If I take a 12.5 degree nominal beam width off the plane of the radome at its center, it clears the spotlight & head rail at the prow by mere inches. Shimming the thing to tilt down 6 degrees results in the bottom of the beam impinging the anchor tackle, irradiating both spotlight casing and front rail completely. Raises doubts about reflections & safety. I get the impression that someone long ago drew the thing up thoughtfully, mounting the radar at the optimal angle for safety and accuracy.

At first glance the beam (as originally mounted) appears to impinge the waterline 60' forward of the prow. But: meaningful targets don't have zero altitude; a 6' high target should be painted at a mere 20' distance. And - my 6 degree shim calculations come from attitude at speed with tabs down as measured by BRNKL... but planing attitude is irrelevant to dark/fog conditions.

My conclusion is: leave it alone; or, if one must shim it down, raise it first so the steeper beam clears the head rail.

[All calculations based on 2011 C26 as originally configured]

/tmm

 

[HookedUp]

On my boats I've used a clinometer app to measure the degree rise at my 'normal' cruising speed and added a wedge to match that degree. If anything it would show boats in front of me better at low speeds and should be good at cruising speed. I've got a Garmin Fantom 24'" radar and it's worked great in fog, rain and clear weather.

Small boats are an issue, but most show up and show their direction (toward or away) or that they are not moving. Larger boats and ships always show up. I use a night camera to see objects in the water and don't expect the radar to show any.

It hasn't picked up crab or lobster pots, but it's done great with pound nets, piers, docks, etc. and at night it's been a real help.