Question: roof rail diameter 16' Cruiser?

[DMcD]

Very disheartened. First, I’m getting chided for playing with too many toys at once. We got a C-Dory to serve as a mother ship for our kayak expeditions. Now it appears we just didn’t do enough research. Who knew this boat was so close to its lateral stability limit that a kayak on the roof would put me in danger of capsizing?? Running the numbers I see that a 50 lb kayak on the roof of a 1000 lb boat would raise the CG approximately 3 inches. Is that all it takes?

I see lots of photos on this site of C-Dorys with all kinds of stuff on the roof including kayaks, canoes and rubber dinghies. I guess those are all larger models that are less “tender” (a new vocabulary word for me).

I really don’t think I could tow a kayak without turning it into an sea-anchor – it’s only attach point is the carry handle.

[spuncopper]

Hey DMcD,

Don't get too disheartened and don't take any "chiding" seriously at all, 'dey jus' be funnin' wid yew win dey chide yew.'

Take the boat out and use it and build slowly from there. The CD 16's will take you out and bring you home safely in weather other boats of a similar size (and some larger) would stay in port over.

The CD's with kayaks, Zodiacs, etc. on their roofs are usually going to be the CD 19s and up. Their beam is quite a bit larger than the CD 16s so they're much steadier.

The CD 16 rides like a WWII destroyer at anchor and at slow speeds, in other words she'll rock and roll. Weight on the roof will enhance the rocking and rolling and slow the recovery time from each roll.

What I meant by "tender" is the CD 16 is "touchy/sensitive" to weight changes. I spent one summer moving a battery storage case loaded with dive weights from one place to another to determine where to put a second battery.

Take the boat out and use it. Be safe. Spuncopper

[spuncopper]

Hey again DMcD,

I was thinking about when I moved 60 lbs of dive weights around in a battery storage case and had a thought...

Counterbalance the kayak with an equal amount of weight mounted on the floorboards on the centerline. Another deep cycle marine battery (approx. 60 lbs) near where the porta potty is located.

Is anyone else is following this, what do you think?

Spuncopper

[MikeR]

Those of us suggesting some caution were just doing so from our experience that the 16' is tender enough without any weight on the roof, but if your lake is small and always calm, maybe it's not even an issue for you...

You might try sending a PM to Brock, aka Catman (member #9 at the top of the Memberlist)...somewhere on this forum is a photo of his 16' Bambina with a small inflatable dinghy on the roof, I'm guessing in the range of 35-45 lbs. He would have first-hand experience as to the effects of that kind of weight and sail area on the roof of a 16. Perhaps it was nothing!

Not to completely hijack the thread, but has anyone ever seen a 1960 Dolphin 16', a 16' flybridge (!) that seats 2? This was a friend's boat from a few years back, a super-rare classic:
http://www.fiberglassics.com/glassic-gallery/category/24-q1960q-dolphin-salty-16-with-flying-bridge.html
Much wider than a CD-16 for sure!

[thataway]

Here is a photo of C pup, at Catalina Island 2012 gathering. He has as much "stuff" on a C D 16 as I have seen. I also saw one which was starting from Seattle area, with the goal of getting to SE Alaska. So these little boats certainly can do a lot more than most 16 foot open boats do.


The beam of the 16 is 6'6", but it is narrower at the waterline, as most semi dories are. The C Dory 22 has Beam of 7'8"--same thing about the waterline beam. We often carry a light weight dinghy--about 55 lbs on the cabin top, There is a slightly noticeable difference in handling.

If I was towing a Kayak, I would put a towing eye on the boat. Although I am not a big fan of towing in rough water, I have often towed kayaks, small and large inflatables up to 13 feet, an Aluminum 12 foot boat, and even a 20 foot walk around Grady White. In each case, I put in a specific tow eye. If you are going to leave the kayak in the water along side the boat you will need attachment points. We are going into the kayak rental business in a State Park, and each of these will have at least two additional strong points installed in the kayak for security and possible tow reasons. You put in a backing block, and drill the holes for screws or bolts thru the hull of the Kayak.

The issue is not just raising the center of gravity--but of changing the characteristics of roll in heavy seas--and though it is not obvious--there are differences dynamically between raising the CG by moving batteries/ and even people in the lower part of the boat, than adding 50 or so pounds on the cabin top. Another issue to approach is getting the Kayak on and off the rack--especially if the boat is not on the beach, and floating in deep water. It certainly can be done, but we use a Davit on most of our C Dories to move even the inflatables to the cabin roof.
Part of this is the weight of a person on the side deck, and then the boat heeling more because of this and the weight of the kayak. It is not going to tip over--but may be a challenge.

No one means to be chiding you--and I believe we collectively feel sorry if our comments came across that way. It is easy to put a couple of foam pads which are made for putting a kayak on a car top, and trying it out--vs putting a rack up there. Walmart carries an"Atwood" foam block set with straps for $20--you might consider giving this a try, before investing in the rack.

Regards,

[Marco Flamingo]

Mike,

Your picture of the small boat with a flying bridge reminds me of a popular well known small I/O boat that seat fours on the FB. Problem was, somebody would catch a fish or something and the four adults would look over the side. The boat would flop on its side. Production was discontinued, but they are still around (sometimes there is one moored by the Fauntleroy ferry terminal). I suspect that two adults would have that effect in the boat in your picture. It looks good, but . . . .

Adding weight down low to compensate for weight aloft is likely just a Band-Aid. You can't get it low enough in a dory to have the same effect as a lead keel in a sailboat. It might slow the roll a little, i.e., make the response more sluggish, but that isn't necessarily a good thing.

I did a lot of white water kayaking back when. 7-10 day unsupported wilderness trips. The normal 40# kayaks would have an additional #40 food, sleeping bag, etc., in them (inside of float bags, so the boat would still float if a wet exit). It made a huge difference in handling. The boats were slow to surface after going over a drop. They were slow to respond to directional changes. It was not as much fun as an empty boat. I learned that the less stuff, the more fun. I didn't think much about the "more dangerous" aspect of a heavy boat back then.

It's a trade off. I wouldn't put a kayak on top of my CD 16, but it is better than putting the CD 16 on top of a kayak. That's a possibility that hasn't been discussed yet. Okay, now I'm giving DMcD a hard time.

I still haven't gotten around to posting my pictures of my recent trip to the Broughtons. We used a bungee cord type of system for going ashore. An anchor on a giant 100' bungee cord was thrown over when approaching shore. I then stepped off with anchor line that was long enough to let the bungee cord pull the boat out deep enough for tidal changes while we hiked or dug clams. The bungee anchor was a small Fortress, so the whole system was less than 5# and stored under the splash well. Worked great and no need for a 50# dinghy towed or on top.

The 16 is so small that I can't carry a lot. It is also so small that I can go into small bays and step ashore. I'm trying to take advantage of what it is and ignore what it isn't. But that's just me.

Mark