Radar question

[SCORPIO]

If you had to choose between the Garmin 18 HD and the 24 HD, which would you choose and why? Both units are 4kw, the 18 had a 5 degree beam width and the 24 has a 3.4 degree beam width. The 18 is a 36nm range and the 24 is a 48 nm range, these are both worthless numbers since I will be mounting it on the arch of my 300 DA so they won't have a horizon that is even 36nm. Just trying to decipher the specs to see which would serve me best. They are close in price so I want to pick the one best suited to my needs.

A little background, I boat on Delaware Bay/Ocean so conditons of short chop and swells are common. We cruise as well as fish. I'd like to be able to see thunder storms coming as far off as possible since most weather comes from the west and that is the direction I have to head for shore, so I want as much lead time as possible to beat it back before it hits. We can get some pretty thick fogs from time to time so I want to be able to pick out boats and other obstructions. I will be hooking this up to a Garmin 3210 plotter and mounting the dome on about a 12" radar mount on top of my factory radar arch to maximise range and reduce the radiation to my head.

Thanks

 

[330DA]

I think you will get more definition from the 24", if you want to see other boats in the fog, as this was one of your criteria. I am in the process of replacing all of my electronics. I went with a 24" HD dome for mine.

 

[CSR_Admin]

They will both work fine for Navigation. The major difference as you pointed out is the beamwidth. So as you approach a channel the 24 will show 2 buoys at the beginning a littler sooner than the 18 would for example. At some point they will both show them as 1 object, and then 2 objects, the 24 will define it as 2 objects a little further away. Same goes for boats. The 24 will difine 2 boats next to each other as 2 separate objects a little further away than the 18 will. Of course whether its one object or 2 you know you need to dodge it, so the narrower beamwidth on the 24 is no big deal. When it comes to dodging crabtraps or smaller objects the 24 will have a much better chance at doing this with the narrower beamwidth. Again, the threshold of it working vs not working is just a little greater than the 18, they will both find crabtraps on a flat calm day.

 

[SCORPIO]

Jim, do you feel the 24 is worth the almost 50% higher price over the 18? From what you posted above, it seems like the two are very close in performance with the exception that the 24 has higher resolving power at greater range. Any specials on either unit coming up anytime soon?