Kayak deck design

[jdupre']

Just think of the untimate floating paddling/fishing platform- the SOT kayak.

Ooooh Joey!, Them's fightin words mate

For the record, the plastic sots that are so popular now, can,will and have, infact, sunk when filled with water. This is why everybody recommends filling the hull with pool noodles.

These pigs of plastic are far from the ulitimate in anything - least of all as paddling machines. About the best thing that can be said about most of them is that they float. :lol:

Mick, didn't say anything about plastic. I was thinking about REAL SOT's made from epoxy and glass. A couple of Matt's designs came to mind. Yeah, lousy is lousy, no matter the design, but if done well, sealed chambers seem the way to go.

 

[Kayak Jack]

Jack
I have listen to you on this subject a few times and I have a couple legite questions,
Now you tell me what you think about how my boat is set up
#1 Cockpit has sealed bulkhead at both ends hatch pretty water tight in both ends 8 inches from bow and stern are bulkheads front and back with non water absorbing foam stuffed in them, these are not sealed water tight (flotation)
#2 I can flood everything on my boat and it will not sink,Its just as easy to pump a sealed compartment out as it is to pump out the cockpit, my boat is not going to stand on end.
#3 Paddling with you at Pk you didn't have a liner in your cockpit (Sock)
#4 Your odds of having a leak in a drybag is better than me loosing a hatch,plus if you do loose your drybags in a roll over you have no floatation, I really don't understand your thinking on this ,am I missing something.
#5 Now I can under stand this line of thinking if you are in a SOF you don't have a choice
#6 To my feeble little redneck mind my boat is safer than yours,I have two devices in place for floatation,sealed hatches and positive flotation locked under the deck. To me a cockpit liner is just a temporary bulkhead and probably not as tough .
#7 On the subject of sealed hatches any pressure that builds will just push out past the seals on the hatches

Wow, let me approach this stepwise.

#1 OK

#2 It is easy to pump out any compartment, sealed or otherwise - IF - you are standing beside the boat on dry land or in shallow water. The problem comes, Ron, when a sea kayak is in deep water away from the shore. Like way out in a lake, or on the Great Lakes, or on the ocean. (Most rivers don't qualify as a large body of water for this description.) When a hatch cover comes off in strong winds or waves - and this happens to paddlers, it is documented - then one end of a boat can fill up and partially sink. Just how partially is dependent upon load, waves, etc. With one end of a kayak submerged, even partly, and the other end up in the air, even partly, a kayak is unstable and will likely capsize. If far from shore and in turbulent water it is serious. If in water a foot or two deep, it is darned inconvenient but probably not deadly.

#3 Right, in a foot or two of water with shore a few feet away, I wanted ventilation more than sea worthiness. So, I had no cockpit liner or spray skirt. I wasn't at sea, so didn't prepare for sea conditions. I prepared for river conditions.

#4 While I have read of kayakers in distress and life threatening danger from lost hatches, I have never read of one in danger from a leaky dry bag. Not real sure I understand what you're driving at here, Ron. I know you have thought it through; I'm just not getting it. Help me out here?

#5 What is an SOF?

#6 Your two hatches and bulkheads actually make it only half as safe as with a cockpit liner. If a boat were to lose the entire cockpit liner it would be in danger. That's hard, because the paddler is sitting on the liner. A boat with two hatches has to KEEP BOTH HATCHES ON to remain out of danger. Your boat, with two hatches, is like an airplane with two engines that needs both of them to fly. A single engine airplane is twice as safe as a two engine that requires both to fly.

#7 Yep. You may be referring to my position about a sealed compartment attempting to attain an air tight chamber. That does not apply to a cargo hold with a hatch. You're right; they will self ventilate.

I hope this helps to answer some questions and clear up muddy waters.

 

[hairymick]

G'day Joey, Point taken mate Sorry, I thought you were talking about the commonly available plastic pigs.

Bear, the reason the plastic SOTS sink is quite simple mate. The plastic they are made of is heavier than water. Tests have been done on this and if they are completely filled with water, they will sink or at best retain neutral boyancy.

Jack, With respect, you are so far off the mark here (in my opinion) that your arguments defy logic. A sea kayak can in no way be compared to a twin or even a single engined aeroplane.

Hatches in sea kayaks have failed before and the reasons for the failure are well documented.

1. Poorly constructed or designed hatch. or -

2. poorly maintained hatch retaining fastenings or

3. inadequate or improper fastening of the hatch hold down mechansms.

In every case that I am aware of, the cause of the falure is builder/designer error or most commonly, User Error

Hatches simply do not fall off on their own, neither will a properly made, maintained and fastened hatch wash off in even the most extreme of conditions. Some may well bemore water tight than others and even the worst of them will only let a little water into the compartment provided user error doesn't come into play.

I don't think the legendary Mr. Verlen Kruger used hatches in his superb boats, but neither are they true sea kayaks. They are decked canoes.

Cockpit liners/ socks, whatever you want to call them may have a purpose in a kayak, but on their own, they do not turn a kayak into a sea kayak. Certainly they may help add safety to an ordinary kayak, but likewise, these two are likely to fail. They are less robust that proper hatches and bulkheads. A kayak in deep water, far from shore with a flooded cockpit is a very bad position to be in. Have you ever tried to wet exit a kayak with a cockpit liner?

I bet my life on my hatches and bulkheads and PFD every time I cross the local bay here to Fraser Island. I know that they will keep me and my boat afloat should the very worst happen and I am happy with that. I don't have a bullet proof roll but I can re-enter my boats in deep water if need be and it is very comforting to know that there is sufficient permanent floatation in each end while I do this.

 

[Kayak Jack]

Hi, Mick. You're right that a cockpit liner will not turn a common kayak (I think, here, you're talking about a "recreational" kayak with a large cockpit?) into a sea kayak. I'm talking about a true sea kayak that has a one man cockpit, and either bulkheads and hatches, or one with a cockpit liner and no bulkheads and hatches. We have to start with proper hull design, and I think we each may have had a different goat pictured in our minds to begin with? Maybe not.

I was comparing probabilities with the airplane example. If you need two of an item to be successful, versus only one of an item, there is twice the probability that one of the two will fail, because there's twice as many of them.

A poorly constructed/made hatch is a lot more likely to fail than a well designed and well made one, I agree. The accident reports did not provide detail about how well done the hatches were, only that hatch failure had occurred, followed by flooding, and paddler distress.

Yes, I've practiced wet exit and re-entry with cockpit liners. No different than out of and back into a boat with bulkheads. Same same. I have only the first half of the roll perfected so far.

I got to thinking last night about Ron's concerns. The boat of mine he saw started life as a true sea kayak, a rather good one too. It is a Pygmy Osprey. I sawed open the deck, and opened up the cockpit about an additional 6 feet, three feet both fore and aft. When I wrote my answers to you, Ron, that slipped my mind. I was responding about a true sea kayak with a one man cockpit. That throws some confusion into the answers and application.

Considering the more open cockpit, and the fact that we were on a river (a REAL shallow river at that) my boat was as safe as yours. We fall over, we stand up in knee deep water in almost all spots. That boat went from being a sea kayak, to being a decked "kaynoe". I still have a Pygmy Coho, like Chucks. They are a true sea kayak, like the Osprey was originally.

My answers apply to a true sea kayak with a one man cockpit.

 

[bearridge]

Bear, the reason the plastic SOTS sink is quite simple mate. The plastic they are made of is heavier than water. Tests have been done on this and if they are completely filled with water, they will sink or at best retain neutral boyancy.

Friend Mick,

I am callin' ya out on this. Come on up here 'n show me. If ya sink one of my SOT's, I'll give a a dollar 'n a 5 lb. bag of Jim Dandy grits. Ya caint fill 'em fulla water cuz they self bail water. Mebbe if ya pulled the drain plug outta the nose 'n put a hose inside? One of 'em even haz a crack in the bottom. We tried shoe goo once, but it didnt hold up in very cold water when it hit sharp rocks (Nantahala), so I jest use duct tape now.

Out in the salt water, there wuz no way fer me ta shove one under water. I never wear a life jacket when I paddle one cuz it iz one big lifesaver.

Mebbe Ocean Kayak SOT's aint like the plastic ones yer talkin' bout? I caint even imagine how anybody kin sink one. Mebbe Ocean Kayak makes 'em outta lite plastic? [chuckle]

regards
bearridge

ps Mebbe it iz magic? lol

Freedom or serfdom?

 

[tx river rat]

I am learning here
Bear The sot kayak has all kind of air pockets and floatation built into them, now a sink Sit inside is a whole different animal.
The only boat I have ever been forced to do a deep water reentry was a plastic sink with no bulkheads and no hatches,That was not a good experience and the no bulkheads was part of the problem ,water ran to whatever the low part of the boat was.
It had foam in the bow and stern but not much,
In my wood boats I tried a couple things ,filling the cockpit full of water and paddling the boat (not a problem) rolled the boat over upside down ,the uprighted it got back in the boat pretty easily. These are personal experiences. I know these work.
Jack your comparision of the plane back up systems surprised me ,it compares to the wing on the plane and a parachute they support each other.

Ok let me try explaining my self again , a cockpit liner is more fragile than a solid bulkhead or my hatches, my positive floatation in the nose and tail of my boat is as bullet proof as I can think of,much tougher than dry bags that can be punctured or leak and the liner and floatation bags both have to be secured in the boat.
The Brazos I paddle has shallows fast water winds and you hit the lakes that are 40 miles long you can hit some waves that are worse than the ocean,there spacing is so much closer. You have to have a pretty versetale craft to paddle it on a steady basis,so this conversation is serious to me not just picking on Jack But i do like to do that too. :evil:
When it warms up a little more I am going to the lake and taking the hatches of and roll the boat, I will file a report and have pics when I do it.
As it stands right now I have to say I still feel more comfortable with solid bulkheads and hatches wit positive floatation in the nose.
Ron
An SOF Is a skin on frame

 

[oldsparkey]

Isn't the main idea to keep the water on the outside of the boat and not inside. If you manage to do that then what is inside the boat does not matter a whole lot unless you forgot the drinks for around the campfire. :lol:

In the kayak with the hatches and bulkheads everything is in some sort of a dry bag because that is how I know where everything is. The color of the bag tells me if it is clothing , tent or the rest of the stuff. I consider the sealed compartments in the kayak as a dry bag or dry area.
In the canoe the gear is inside dry bags inside large dry bags and one is in the bow , the other in the stern while the food , camera and camp chair are near the middle of the boat.

Yep... Dry bags inside dry bags , dry bags are only dry if the water does not get into them and double duty does the trick for me. Actually on this last trip , leaving the campsite one was a dry bag and the other was a wet bag since it was packed with all of the wet stuff which keep the canoe dry. Plus later when it was packed in the Jeep it keep the Jeep and the dry stuff dry till I got everything that was soaked dried. :?

Chuck.

 

[bearridge]

They quit makin' a whitewater SOT (the ones I got), but this one iz close. I dont figger any of ya'll kin sink one. I paddled one of mine way out in the ocean when the swells wuz high 'n they had red flags up 'n down the beach. When I got our purty dang far, I found a spot where I seen the bottom. I rolled off, swam down lookin' fer sand dollars 'n come back up. I crawled back on top 'n paddled back in.
http://www.oceankayak.com/images/kayaks ... ig_yak.jpg

 

[hairymick]

Jack,

Any kayak, regardless of hull form will not be recognized in Australia as a sea kayak unless it has bulkheads hatches, decklines and other self rescue paraphenalia considered by ourgoverning body, Australian Canoeing. This is the body that sets minimum safety standards for all the affiliated sub categories here.

These minimum standards are what is required to participate in any event that requires the use of a true sea kayak.

Like you, i like a bigger than standard cockpit opening. I also rarely wear a spray deck/skirt unless playing in the surf often to the chagrin of my colleagues who insist on wearing the things even in still water. My safety lay in the design and integrity of my boats, their hatches and bulkheads and their unquestioned ability to remain afloat. No hatch has ever failed for me, even in repeated forays through big surf.

In our modern "blameless" society, that fact that a hatch might hve failed is often reported but the causes of the failure rarely are. To me it would make sense for those so called "reporters" of these incidents to investigate more fully to gain an understandong of how and why the hatches failed rather than the sensationalization of the event itself. The reports I have read all seem to go like this "Paddler X's hatch cover came off and his forward hatch got completely filled with water and so on and on. Nobody seems interested in asking "why did it come off" I believe nine times out of ten, at least the answer would be because the idiot didn't fasten it properly.

Bear mate, I am talking specifically about Ocean Kayaks and so many others of the same ilk. If the hull integrity is compromised sufficiently or a hatch falls off and he hull is filled with water these boats will sink. All the retailers here recommend the insertion of pool noodles in them, just to keep them afloat should the worst happen.

 

[Kayak Jack]

Ron & MIck,

While I wouldn't be fearful of a boat with bulkheads and hatches, I just prefer to not have them, and would rather use a sea sock, or cockpit liner. If you had two identical sea kayaks with a one man cockpit, one boat with good bulkheads and another with a cockpit liner, upon capsizing equal amounts of water would be taken on board.

And, each cockpit would be emptied by a swimming paddler raising the bow of an inverted boat to drain the cockpit, and then flip it over. Establish the paddle float and crawl aboard. Keep the paddle float rigged while putting on the spray skirt (if equipped) and pumping out the remainder of the water with a pump down the tunnel of the spray skirt. Recover the paddle, stow the float, and paddle off. Both self-rescue techniques are identical whether a boat has bulkheads or a cockpit liner.

I paddled with the same liner for over five years before I snugged up the elastic, then paddled another two years. They are a robust item, and take a lot of beating.

Even a dry bag that had a leak would provide flotation for a very long time. And, mine don't leak. (Duct tape is wunnerful.) Makes no difference, because water doesn't get into my cargo holds; my liner stops it just as effectively as a bulkhead.

I have difficulty understanding why you guys cannot understand my airplane example. It's about probability of either of two units failing vs only one of one unit failing, not about airplanes or boats.

Almost all hatches are functional and remain on during even rough conditions. Only a very few have failed, but the penalty for error was catastrophic in some cases. Bulkheads have failed too. Some boats have a 2"-3" wall of closed cell foam glued into place. Pretty wimpy bulkhead in my opinion, and I would not trust one. Even shifting cargo in a tossing sea could knock out one of them.

Ron, your boat is good; it satisfies you.

 

[tx river rat]

Jack
A fail safe system means you have a back up system in a plane ,boat car are whatever. It just takes one to work but has another system in place in case the first one fails. In your boat your liner is your first system and dry bags the back up if you blow the liner.
In my boat the sealed hatches are the first system, the positive flotation in the bow and stern are my back up system.
It doesnt not take both systems to operate just one.
This is one of those subjects that we are going to have to agree to disagree.
Now for folks that are new here Jack Myself Mick ,all of us voice opinions on this forum ,we dont get mad but I have learned a lot
looking at different prospective from different folks.
Sometimes I will ask a question I am not sure of,even if its controversial just to be able to see the different prospective
Ron
I went back and checked with my buddy that races yaks here ,one of the rules is you have to have a water tight hatches on the boats before you can enter

 

[bearridge]

Bear mate, I am talking specifically about Ocean Kayaks and so many others of the same ilk. If the hull integrity is compromised sufficiently or a hatch falls off and he hull is filled with water these boats will sink. All the retailers here recommend the insertion of pool noodles in them, just to keep them afloat should the worst happen.

We aint talkin' bout the same kinda boat. Ocean Kayak iz a company. My whitewater Ocean Kayaks dont have no hatches. They are SOT 'n they are self bailin'. Ya caint sink 'em. They are like one giant life saver....'er a big log. Fall 'er jump off 'n climb back on. Mebbe it iz the self bailin' where yer apple 'n my orange dont meet?

Ya jest caint sink one of my Ocean Kayaks.......on the ocean, on a lake 'er in a river. Wont ya come over here 'n take my challenge? [grin] I'll make it two five pound sacks of Jim Dandy grits if ya prove me wrong? Mite even throw in some bent tent poles and a Croc....right foot az I recall?

regards
bearridge

Mr. Corleone never asks a second favor once he's refused the first, understood? Tom Hagen

 

[gbinga]

Bear / Mick - Some plastic sit-on-tops have hatches. Some don't. I've seen them both ways. I'm awfully surprised to think that one would sink if the hatch popped off--- I would have assumed that they'd be required to have enough foam built into them to keep that from happening!!! Aren't all small craft required to have some minimal level of flotation? (I'm thinking that's a requirement here in the States)

Jack - I get it about the airplane. If both engines are required for flight, then a failure of either means you are coming down. So you have twice as many opportunities as with a single engine plane.... makes sense to me. Same logic would apply to a two hatch boat vs. a one hatch boat, assuming that one hatch failure results in an unacceptable condition.

I'm not trying to enter the debate here. I haven't spent any real time in kayaks with hatches, so I don't have a clue how likely hatch failure would be.

George

 

[hairymick]

Jack,

Precisely, what holds your cockpit liner in place? Is it attached to your cockpit coaming like your spray deck? and under the spraydeck bungee.

If so, What is to protect your hull and airtight integrity should you need to do a wet exit? What allows you to safely remove the spraydeck from the coaming lip without also removing the fitted lip to your cockpit liner or sock?

I have used quality dpray decks properly fitted to my coamings in heavy surf, and can tell you that in the rough and tumble of those conditions, it is not unheard of for the waves breaking on and all over the boat and paddler, to lift the spray deck from the coaming. I would imagine a similar thing happening with the cockpit liner thereby reducing the floatation in your boat to whatever you happen to be carrying in it.

I think it is a very dangerous thing to advocate the use of a cockpit liner instead of hatches and bulkheads.

 

[Kayak Jack]

Mick,

Yes, the liner goes over the coaming, under the spray deck. I have never experienced a liner coming loose in either a wet exit when I ripped off the spray deck, or in wind or surf. I have never read any accident accounts of one failing either.

Everything and anything can fail. So far, I have not seen any documented cases of a liner failing. Some may well have and I didn't read or hear of it. No professional trainer or author I have read or heard has ever said to avoid cockpit liners. So far, you are the first. I'll keep my eyes open for other warnings, Mick. Thanks.

 

[tx river rat]

Ok I am going to get into this one more time
I talked to Jack and I understand his thinking on a twin engine plane,but I drive a car that has four wheels and it want go if there not preforming.I rode motorcycles they have two wheel does that make them safer, could try a unicycle with just one tire but I would sure not be safe then.
I really think this is a conversation more about local traditions than preformance. A skin ON frame yak needs the things Jack is talking about to be as safe as it can be,and Jack is close to the home of that style yak,Mick Hates the sit on tops that they use here in the gulf ,but I think the surf conditions have a lot to do with that,I am not a canoe person and it is because of the conditions I paddle n. It reminds me of a very smart friend of mine and a talk we had about buying realestate ,his favorite saying was location location location ,that was his first thought about buying a piece of property.
I am going to break this down a little different
Cockpit liner is just one piece of equipment ,thats true but if it fails you flood the whole boat,both ends
Hatches ,there are two of them,Jack says they are twice as likely to fail, hunnnnn now that means I have to have two failures to match up to his one with a liner to be in the same shape.
Dry backs ,flotation bags they will float the yak , but need to be secured and make sure nothing sharp hits them,they will work.
Positive floatation in my boat is secured in the hull ,can't leak ,the pool noodles I use will not absorb water,I have 2 flotation devices In the hull Jack describes he has 4 6 or 8 so that goes against the two engine thing again.
To sum this up saftey wise
Covinaice wise, I will go with my hatches ,It is much easier to access my gear ,loading my boat is easier and I do not have to have multiple dry bags. my floatation is there in place ,will not move leak or really have to be maintaned at all.
Saftey wise The odds are better that Jacks system will encounter problems than mine ,installing the sock correctly every
time a less durable material than my hatches and bulheads, Packing the dry bags correctly and making sure there sealed,making sure they are secured in the boat
My floatation is just there.
I guess this ole redneck likes the kiss principle ,strap down to hatches, flotation is there,easy access, no dry bags inside the deck,nice and simple
Jacks system packing several flotation or dry bags ,harder access, running ropes under the deck to pull your stuff out
installing the sock.
I think both systems will work if used right ,for me if I was in the open ocean ,I would want a spray skirt ,good hatches and positive floatation , for me that would be the most reliable system.
Wheeeeeeeeeee dang thats a lot of typing ,if we keep this kind of conversation up I am going to have to get me a secutary.
Ron

 

[bearridge]

Some things float.....others dont. On the Brazos I went ta clean off the communist table I figgered wuz mine ('er Darrell's). I laid it in the river 'n by gum it floated. Didnt have no liner. Didnt have no pool noodles. Didnt even have no air bags.

I dont know if all plastic floats. I never studied plastics at the Bodine School. Ocean Kayak must use the kind that floats. It dont have no foam, no liners 'er pool noodles inside. Like my communist table, it jest floats. Not az good when a big fella like me sets in it, but unlike the Titanic 'n the boats ya'll are talkin' bout, it will NOT sink.

Now I gotta admit I never cut (melted) one open, so I dont know if any elfs 'er little Irish people iz inside workin' magic. What kinda wood do ya'll use that dont float? I have noticed that some of it iz heavy. Remember them little nickel airplanes we used ta put together 'n fly when we wuz little pardners (gliders). That wood likely wont sink. Mebbe all that glue makes it sink? Mebbe it iz all the heavy gear ya'll tote in 'em? [grin]

regards
bearridge
bodine college

ps Ever paddled a witch? lol

BEDEVERE:
So, why do witches burn?
[pause]
VILLAGER #3:
... 'cause they're made of... wood?

 

[a Bald Cypress]

I spent a bit of time looking around the house and finally found a couple of pennies under the dirty laundry so I can add my two cents to this discussoin.

My kayak is home built, a One Ocean Cape Anne Storm. It is 16 ft with three [3] sections or compartments.
Two hatches, one for the forward and one for the rear. Bulkheads at the ends of the cockpit to keep the fore and aft compartments separate and dry. On my build, the hatches are held in place with magnets, I think, off the top of my bald head , that I used six on each hatch spaced around the edge.

NOW: I have never had my boat in rough surf, wild winds or rushing rivers. I have taken it to the lake and experimented a bit. Taking the hatches off and filling the boat completely will not sink it. It just floats lower in the water.

Removing one hatch and just filling either end will not make it stand on end as some have said. It tilts a bit is all.

One end and the cockpit filled will tilt it a bit but nothing too severe.

I have therefore concluded that additional flotation is not required FOR MY use.

YMMV.

Respectfully submitted for review and criticism by any and all.

 

[stickbow]

Any kayak, regardless of hull form will not be recognized in Australia as a sea kayak unless it has bulkheads hatches, decklines and other self rescue paraphenalia considered by ourgoverning body, Australian Canoeing. This is the body that sets minimum safety standards for all the affiliated sub categories here.

These minimum standards are what is required to participate in any event that requires the use of a true sea kayak.

So...

The original (and still used by a lot of people) Skin on Frame (SOF) kayaks are not sea kayaks? We should let http://www.qajaqusa.org/ and the rest of the Greenland Kayaking Society know...

Betcha ten USD that any Australian could look at a Greenland kayak and recognize it as a "kayak" :lol:

Yeah, I know it's a legal definition related to insurance/litigation bull caca. It just seems odd -- like "no gasoline powered vehicle without airbags can be called a 'car'."

'least here in the states commercially produced boats just have to demonstrate neutral bouyancy - all of 'em, I believe.

Somewhat back on topic. I have bulkheads in some of my 'yaks, but I still put float bags (or dry bags with enough air to help float it) in them. Hatches and bulkheads, no matter how well designed can have failures - human error or bad design or killer whale or whatever. However, I do not wear suspenders with my belt usually

 

[hairymick]

LOL,

G'day Stickbow,

Mate, it is not my call - and I wouldn't dare call a true Greenland kayak as anything other than a sea kayak.

I merely used the reference as to what will qualify as a true sea kayak here to be allowed to participate in any sea kayak specific event that is sanctioned by Australian Canoeing.