Do I really need a radar arch?

D

drbridge

New member
This is a question I keep contemplating. Our recently acquired 22 Cruiser has a very nice low radar arch with 6 rocket launchers and antennas. It looks very nice and is quite functional. The only draw back to this set up is that we would like to carry an inflatable dinghy and with the low arch the biggest one we could possibly fit would be 7'6". I don't have a lot of experience with inflatable dinghies, but I am thinking we might want something slightly bigger. The 7'6" models are rated at around 420lb carrying capacity. while the 8'6" models are rated at 70% more and not that much heavier.
My next question is how many C-Brats have used a 7'6" dinghy and what did you think of it. Susan and I would just like something we can row for short distances. we don't want to pack another motor.
our other options are:
1 get a high arch at great expense and hassle.
2 Extend the current arch (Might be just as much $ and hassle as new one)
3 remove the arch and mount radar on front of roof as I have seen on many other C-Dorys and put the dinghy over the radar. ( still a hassle but may be less $ )
One more question. Is there much difference in performance for radar that is mounted high and those that are roof mounted?

Thanks

Doug & Susan
 
The RADAR performance gain from rooftop to low arch position is not a big enough factor to worry about. Arches can be handy as handholds and mounting points for other items so I would try to keep it as plan A. The right shop could surely raise your existing arch so that should be kept in mind as well.

How much clearance is under the arch? It might be enough for an inflatable with smaller tubes like this.

http://www.alpineboats.com/crossovers-k ... aboat.html

We have the 14ft model and love it.
Greg
 
I have owned a number of inflatables over the last 50 plus years, including some which were no bigger than a bathtub. We used one of the smaller boats for both the Broughtons and Alaska--both trips over a month, and with a small dog. The 8' 6" model has considerably more room, than the foot shorter model--remember that the length is over all, and the extra foot is in the part where you sit and row. Don't discount a small dinghy motor, which can do double duty as a "kicker" for the C Dory 22. I use a 3 1/2 HP 2 stroke--about 30 lbs, and will push the C Dory 22 at about 4 knots in calm water. (Some will say you need 8 hp plus--I have handled boats the size of the C Dory 25 with a 4 hp outboard--and it can be done safely, but you have understand what that will do, to get you to safety, and out of any danger.

The bigger boat will row much better. I probably would investigate extending the current arch. If you change, you probably will not be able to match the bolt pattern, and holes used for the wiring. If you go to the separate support, again you have a bunch of holes to patch, gel coat to match etc. I agree with Greg in all other respects.
 
one other consideration for the diggy that i've ran into with my parents, weight. You don't want to hurt yourself getting and awkward object like that up onto the roof.
 
One other consideration for the diggy that i've ran into with my parents, weight. You don't want to hurt yourself getting and awkward object like that up onto the roof.
Click to expand...

Conrad, We have owned the following dinghies thru the years: the slat floored dinghies in the 6'7" size range Bombard AX1, is in the 33 lb range; the 7'8" AX2 slat floor, is about 40 lbs and 8'6"AX 3 is about 50 lbs.

Currently we have an 9'6" High pressure air floor weight: 68 lbs. All of the slat floor dinghies were manageable (my age during this time was in the early to mid 70's and I have had back surgery). One person on each side is able to slide the boats up on the side of the cabin house. One hand on the boat, and one on the hand rail. It may take two "lifts", and a line can secure the boat between each lift if necessary. We usually use the "release and grab" a foot further down the hand rope on the side of the dinghy.

With the 9'6" current boat, we installed the Garhauer davit, so we can put that up on the roof fairly easily with only one person--I am now 78, and had a second back surgery about 18 months ago. So these size dinghies are manageable on a C Dory, with the right technique. Another technique with larger dinghies is to bring them first onto the foredeck, and then to the cabin house top.
 
Another thing to consider - if you can get the dinghy over the top of the radar arch, you can leave one end of the dinghy over the radar. Radar passes through the dinghy just fine.
 
Doug and Susan,

There may be other options.
1. Mount the dingy forward of the arch.
2. Move the arch forward, and put the dingy up on the aft cabin roof.
3. Think outside the box a little, put the dingy even farther aft. :wink:
4. Roof mount the radar and put the dink over it

Or find something new. New can work, if it gets thought out well. (See Greg's 25, Aurelia, with the Portland Pudgy on the roof for instance.

If you want to try a doughnut dingy, you are welcome to try mine. It is aN Alaskan twin.

Harvey
SleepyC :moon

1_10_2012_from_Canon_961.highlight.jpg
 
thataway":4e87x0k6 said:
One other consideration for the diggy that i've ran into with my parents, weight. You don't want to hurt yourself getting and awkward object like that up onto the roof.
Click to expand...

Conrad, We have owned the following dinghies thru the years: the slat floored dinghies in the 6'7" size range Bombard AX1, is in the 33 lb range; the 7'8" AX2 slat floor, is about 40 lbs and 8'6"AX 3 is about 50 lbs.

Currently we have an 9'6" High pressure air floor weight: 68 lbs. All of the slat floor dinghies were manageable (my age during this time was in the early to mid 70's and I have had back surgery). One person on each side is able to slide the boats up on the side of the cabin house. One hand on the boat, and one on the hand rail. It may take two "lifts", and a line can secure the boat between each lift if necessary. We usually use the "release and grab" a foot further down the hand rope on the side of the dinghy.

With the 9'6" current boat, we installed the Garhauer davit, so we can put that up on the roof fairly easily with only one person--I am now 78, and had a second back surgery about 18 months ago. So these size dinghies are manageable on a C Dory, with the right technique. Another technique with larger dinghies is to bring them first onto the foredeck, and then to the cabin house top.
Click to expand...

I've got a design in my mind for a hand winched dingy cradle that can raise a dingy up on top of the roof with only using the winch. It's based off a great design that they used on one of the dive boats i worked on as a kid. I'm not going to build one, the clean a jerk method is working well so far. But if anyone else is interested i'd draw the concept out.
 
Thanks for all the helpful input.
The Arch we have now is 7" above the center of the roof and will not allow any inflatables to go underneath of it at the present height. I called a local welding shop that does reputable work and they said they could make the modification, but that polishing it would be time consuming ($$). I will have to tow the boat down there and get an estimate. If I go with raising the current arch, it appears I could reuse the holes for the rear mounts. Because of opposing angles of the front and rear legs it would be necessary to drill new holes for the the front mounts. It should not be too hard to patch the old ones.
As far as mounting the boat in front of the Arch the 8'6" that I am considering would hang at least a foot over the front.
Think outside the box a little, put the dingy even farther aft.
Click to expand...
Harvey, when I saw your boat parked out on the street a while back it had some bars at the rear of the boat and I wondered if this was a rack for carrying a dinghy above the cockpit. Was that the case?
Conrad, We have owned the following dinghies thru the years: the slat floored dinghies in the 6'7" size range Bombard AX1, is in the 33 lb range; the 7'8" AX2 slat floor, is about 40 lbs and 8'6"AX 3 is about 50 lbs.
Click to expand...
Bob, The AX3 looks like a neat boat. I have searched on the internet and the only ones I could find for sale were in the UK. Is there a dealer in the US?
We also are looking at the Saturn SD260. It has an inflatable floor and is reasonably priced. From the research I've done the inflatable floor is a nice feature when you are rowing the boat. It is a bit heavier than the AX3

Thanks again for the ideas

Doug & Susan
 
Doug,

Yes. It is a three part arch, with the bases permanently fixed to the splash well walls and sockets for fitting the uprights into. The top, cross piece, lifts off the uprights, and all three pieces will lay in the "hallway" in the cabin.

Easy, removable, and serves as cockpit cover, and inflatable storage.

1_10_2012_from_Canon_961.sized.jpg

Harvey
SleepyC:moon

Though in our sleep we are not conscious of our activity or surroundings, we should not, in our wakefulness, be unconscious of our sleep.
 
Doug, The West Marine WEST MARINE PRU-3 Performance Roll-Up Inflatable is what was the Bombard AX 3. I used the AX series, since my first small boat was of that series (the 6'7"). The 8'6" boat I owed was the West Marine 260. Not a planing boat, but rows fairly well and does very well for a light weight dinghy.
 
That is a nice set up Harvey. What size is your dinghy?
I looked at the West Marine PRU-3. That is a neat little boat and amazingly has almost 20 times the carry capacity as the weight of the boat.
 
Thanks, I'm not with the boat right now but I will check and let you know. I think it is about 8 ft, end to end. It weighs about 40-50 pounds. I should know that but I don't remember. I know I can easily handle it, from the water to the rack, and carry it on the ground.

ON EDIT: It is a sister boat to the Alaskan 240TDS, 45# and 7'10" long, pay load about 800#.

Harvey
SleepyC :moon

1_10_2012_from_Canon_961.highlight.jpg
 
No, you do not need a radar arch.

I mounted my radar dome forward on the brow with the back of the dome even with the anchor light. I mounted it on wooden supports that distribute the weight from the brow to the more solid roof over the windshield.

With the dome forward, I carry a R-260, 8.5 ft inflatable on the roof. There is room for the dingy, the anchor light, and still have the dingy not interfere with my Bimini which connects to the aft roof but is about 10" higher than the roof.

Rick from Maine
 
We have carried our 12' Saturn KaBoat like Hardee does, with good results.

We have also pulled it up over the gunwales, just ahead of the outboard, and carried it that way. When returning to the dock, it's easy to pitch it over the side and tow to the slip.

You are welcome to experiment with our KaBoat if you wish.

Jeff
 
Hi Doug and Susan,

I too have the lower radar arch. I have the Bombard AX1 (6' 7") as mentioned by Dr Bob. At 33 lbs I am able to sling it from the water on to the roof with one hand. This is very convenient as I am in my 60s and do not have a davit. I have owned, and used, this dink for 13 years. Had I been buying new today I would be looking in the 7' 6" range. Yes a bigger dink (8' plus) would be a better row but how many times a year are you actually going to use it? I would not go to the expense and labour of changing the radar arch and wiring. Not worth it for the handful of 'rowing ashore' trips per season. Work with what you have, it is cheaper.
Another option is the inflatable kayak route. We carry a couple, they sit in the dink on the roof. Great if you are not lugging Fido, the BBQ, and other crap ashore.

Martin.
 
Hey, hey! Don't be messin' up the beautiful lines of that boat. :mrgreen:

Two thoughts I'll toss out there. First up - call me paranoid, but there's no way I'd put the radome directly on the roof. Yes, others have done it - but I'd simply not be comfortable standing in the cockpit with that era of RADAR running. Particularly given that you have floorboards and the low roof. Me - I'd want that radome and its beam path well above my head (and that of any of my passengers) as it is now.

RE the dink - Gary King's Alaska TDS Series have received gobs of praise here for good reason. Yes, they are pricey - but they go on sale every time Gary hits up a boat show, and if you keep your eye out on craigslist you might score a great deal on one like I did. There are three things about them I find separates them from the crowd:

- Weight. They are amongst the lightest for their size, and other brands that are close don't fare as well when it comes to the next bullet point.

- Durability. The Grizzly claw bottom is insanely tough - much more so than straight Hypalon. You won't give it a second thought taking it ashore in ugly places. If you just want to get to the dock or sandy beaches, perhaps not a concern...but for me, knowing it's near impossible to puncture brings peace of mind.

- Short or long shaft. Yes, they state long shaft is required - but it's not. Trim down the mounting plate a bit, and a short will work fine - I've the Honda 2.5 on mine. Or, stick with the long and toss your kicker on it. Probably not an easy task given the weight of your kicker, but it would work. Too bad you got rid of that lightweight 5HP... :D

I've the 270TDS, and can get it up top of the Nordic roof by myself without much trouble - it only weighs 50 lbs., even though it's almost 9' long. My guess is, it's probably a tad long even if stowed like Harvey does - a 240TDS would probably work better. Still, if you want to give it a try or take a peek, lemme know.
 
I agree with Bill. I would not put the Radar dome right down on the roof. Too close to my head. I like the stand, to get it up off the roof. Dingy can go over that, with some support for the dingy tubes the weight is not on the raydome. The radar can see through the inflatable.

Harvey
SleepyC :moon

HH_Cal_09_07_Jul.thumb.jpg
 
hardee":fzs7x7ca said:
I agree with Bill. I would not put the Radar dome right down on the roof. Too close to my head. I like the stand, to get it up off the roof.
Click to expand...

I don't have radar yet (and may get broadband anyway), but I have been thinking about it because it is on my "want" list. Just thinking about the above statement and wondering about a contrarian view (not contrarian to your feeling about it, because just wanting an arch is the only reason necessary) but to the objective part about the beam).

1) I thought it had been shown by the angles/cones that if the radar is mounted on the roof, it won't negatively hit you at the helm or in the cabin or cockpit.

2) So where I would worry about it is going up the sidedecks and doing foredeck work. Then I wonder if the arch (especially the low one) would really help or if it would be a false sense of security (because you'd be in the beam anyway)?

I don't know - but it's something that came to mind.
 
Holy Crap! I hadn't even given any thought to health at this point. Now I will have to think some more.
I guess trying out the largest size dinghy (7'-6") that will fit with the existing low arch would be the quickest and easiest thing to do. I have a lot of other things to work on, routine motor maintenance, some cabinetry work in the cabin, installation of Atwood fuel tank vents (Sunbeams Mod), a complete waxing of the boat and a few other small mods that I have in mind. That is not to mention installation of wiring in the new boat barn and also in my old boat shed that I told Susan she could park her car in since I tore down her car port to build the new boat barn. Oh yeah, All my trucks and cars are do for routine maintenance and then there is the kitchen remodel that I was 1/4 of the way in to when we bought the C-dory in July and have not touched since.
I guess I will have some time to think it over and will look on Craigs list for a deal on a 7'-6" dinghy. If that size works for us we could then purchase a new one of the quality we would want. If we need something bigger we'll have to go from there.
Harvey, Maybe sometime we could take a look close up of your dinghy, as it sounds like it might be small enough to fit in front of our arch. have you rowed it with 2 adults, or do you always use a motor?
Thanks for all the thoughts and great advice, it definitely gives food for
thought.

Doug and Susan
 
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