Do I really need a radar arch?

drbridge · Posted: Wed Oct 15, 2014 3:41 pm Post subject: Do I really need a radar arch?

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

Aurelia · Posted: Wed Oct 15, 2014 5:12 pm Post subject:

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-kaboat/22-saturn-12-inflatable-boatkayak-crossover-kaboat.html

We have the 14ft model and love it.
Greg

thataway · Posted: Wed Oct 15, 2014 5:35 pm Post subject:

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.

cmetzenberg · Posted: Wed Oct 15, 2014 9:54 pm Post subject:

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.

thataway · Posted: Wed Oct 15, 2014 10:25 pm Post subject:

rogerbum · Posted: Wed Oct 15, 2014 11:22 pm Post subject:

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.

hardee · Posted: Thu Oct 16, 2014 1:51 am Post subject:

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

cmetzenberg · Posted: Thu Oct 16, 2014 2:59 pm Post subject:

drbridge · Posted: Thu Oct 16, 2014 3:23 pm Post subject:

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.

hardee · Posted: Thu Oct 16, 2014 3:43 pm Post subject:

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.

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.

thataway · Posted: Thu Oct 16, 2014 5:35 pm Post subject:

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.

drbridge · Posted: Fri Oct 17, 2014 8:17 pm Post subject:

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.

hardee · Posted: Sat Oct 18, 2014 1:20 am Post subject:

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

Rick from Maine · Posted: Sat Oct 18, 2014 8:10 am Post subject:

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

Captain Bella · Posted: Sat Oct 18, 2014 5:31 pm Post subject:

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