Can a fully laden kayak sink if swamped?

[leighv]

I’ve often wondered about this so figured I’d put it out for a discussion. Since a flooded cockpit adds considerably to the weight of a boat, could this potentially cause a fully laden expedition kayak to sink, or would the neutral buoyancy of water in water, combined with the pockets of air in the hatches, prevent this?

Has this ever happened to anyone here?

And as a bonus question, is it harder to roll your boat when it’s fully packed? I’ve only ever rolled my boat when empty.

[Chris Bolton]

Normally, well sealed drybags have quite a bit of buoyancy, plus any air pockets. If the boat is upright the cockpit could fill up to the rim and add weight, but only if the water in the cockpit is higher than the sea - and if the cockpit rim is higher than the sea the boat isn't sinking. I've never heard of a loaded kayak sinking. An empty kayak with holes or badly leaking hatches could sink.

Rolling a loaded boat is fine provided you slow down the roll and give it time to move. It also has momentum once rolling so you need to be aware and not roll past upright and back in on the other side.

A partly loaded boat with heavy things that drop down to lie on the deck when inverted can be more difficult to roll.

[PlymouthDamo]

I've done the experiment....

My rolling boat is extraordinarily low-volume, to the extent that people on the beach will pass comment about how I look like I'm sunk when I'm paddling around. So, after I'd installed a new deck hatch which introduced the possibility of water getting into the front compartment, I decided to test out whether I'd actually sink were this to happen. So I fully removed the front hatch and allowed the front of the boat to completely fill to the top with water. It didn't sink, so I then removed my spraydeck and allowed the cockpit to completely fill with water. It still didn't sink, so I then paddled it back across the River Tamar for approx. 1 mile, keeping up with the rest of my group. At first, the handling was a bit twitch/wobbly, but by the time I'd got back, I'd got used to it and it felt okay. I do have a buoyancy bag in the front - I'm assuming that without this it would have been 'floating beneath the surface' and trying to paddle the thing would have been a bit more problematic...

Sounds like a daft experiment, but a couple of months ago I found myself in a situation where I was really grateful that I'd done it. I'd swapped my rolling boat with someone who was thinking of building one, and whilst we were having a day out, they managed to put a large hole in the rear deck. (How that happened is another story which I'll eventually get round to writing about on the Shrike thread.) This meant my largish day-compartment would almost instantly fill with water, and it's the rear of the boat that sits lowest and is often underwater at the best of times. This happened on a beach in surf (that was big enough to have made one of our buddies decide not to paddle) and we needed to go along the shore for a mile or so to get back to the bay we'd launched from. If it hadn't been for my daft experiment, I'd have probably given up on the idea of paddling back and gone with the complicated car shuttle option. But the experiment gave me the confidence to at least try it, and the boat paddled absolutely fine in the surf despite the day compartment being completely filled with water. Rolling was actually easier during my fully-flooded bow and cockpit experiment, which makes sense: it's easier to right a boat when your centre of gravity is lower. In practice, it felt like it didn't want to capsize, and was then desperate to help me get it back the right way up.

So.. I'd imagine that it would take a hell of a lot of flooding before a normal sea kayak could no longer be paddled and I'm not sure whether it would ever fully sink. If you haven't got a load of luggage in dry-bags, you ought to have a buoyancy bag in each of the two large front/rear compartments - my experience was that this was enough to save the day no matter how badly flooded you were. That said, wind, swell and currents can conspire to make the handling of a flooded boat really difficult as I've discovered on a different occasion when my cockpit had flooded because of a large hole in my spraydeck.

[ian johnston]

Hi Leigh,

I've unintentionally tried the fully swamped boat test....it didn't sink! After the interesting experience of being "washing machined" in a gully full of aerated water, then following my boat over into the next gully on a big swell it was completely swamped. We had relatively full boats on a winter camping trip so there wasn't a lot of empty volume (air) in it.

Whilst very difficult to manoeuvre when fully swamped and requiring a mighty bow-lift to part-empty the cockpit by pushing up from in the water I didn't see any risk of the boat sinking or even submerging, which was nice!

The sorry tale is best told here: https://seakayakphoto.blogspot.com/2012 ... inlet.html

Hope this helps :)

Ian

[mrcharly]

I can confirm that a racing K1, lacking air bags, sinks very fast and is incredibly difficult to keep on the surface.

(entirely my fault; the boats are always transported without the bags in, since they have a tendency to blow out. I hadn't checked for bags before taking an unfamiliar and very tippy boat out)

[Chris Bolton]

I've unintentionally tried the fully swamped boat test....it didn't sink! After the interesting experience of being "washing machined" in a gully full of aerated water, then following my boat over into the next gully on a big swell it was completely swamped. We had relatively full boats on a winter camping trip so there wasn't a lot of empty volume (air) in it.

Just checking that we're all discussing the same thing! Was that a fully swamped cockpit and full loaded but dry hatches? There's no question in my mind that I'd expect that to float - I understood Leigh to be asking about a fully swamped cockpit AND flooded hatches full of gear?

[leighv]

I've unintentionally tried the fully swamped boat test....it didn't sink! After the interesting experience of being "washing machined" in a gully full of aerated water, then following my boat over into the next gully on a big swell it was completely swamped. We had relatively full boats on a winter camping trip so there wasn't a lot of empty volume (air) in it.

Just checking that we're all discussing the same thing! Was that a fully swamped cockpit and full loaded but dry hatches? There's no question in my mind that I'd expect that to float - I understood Leigh to be asking about a fully swamped cockpit AND flooded hatches full of gear?

Just to be clear, I meant only a swamped cockpit, not swamped hatches too! :)

Ian’s experience certainly sets my mind at ease. I’m preparing to go on a multi day trip again and at times like this, the question of sinking always starts to float around my mind again. I’m a real “worst case scenario” type 🤣

[leighv]

Thanks for sharing your thoughts and experiences! I figured a sea kayak would probably still float, even if, as some of you have confirmed, it becomes extremely difficult to handle. So it’s good to hear that the boat won’t suddenly fall into Davy Jones’ watery clutches!

I guess I should really practice rolling with a packed boat sometime…

[Chris Bolton]

Just to be clear, I meant only a swamped cockpit, not swamped hatches too! :)

Ah, sorry, I misunderstood. I'm quite sure a loaded boat with a swamped cockpit would float. I've done a rafted tow of a fully loaded kayak with swamped cockpit and 85kg of paddler (I didn't empty the cockpit before getting him back in as he was having a diabetic hypo and my priority was to get him out of the sea) plus a half swamped front hatch (the hatch rim had a crack that was opened up when the gear dropped onto it in the initial capsize). It didn't even cross my mind that it might sink, but it was a pig to handle as the bow was deep in the water.

The Sea Tiger was an unusual boat designed in the 1980s by Alan Byde, and had a pod cockpit instead of bulkheads. This meant that the whole boat apart from the cockpit was one compartment. Although it had 2 hatches, the front and rear compartments were connected around the cockpit.This was sold as a safety feature, on the basis that if the boat was holed, it would fill both front and rear so would remain level, and the stowed gear would keep it afloat, rather than either bow or stern being down and making the boat unsteerable. There was quite a controversy about it at the time and the ability of the boat to float with gear and swamped compartment was actually tested - it did float.

[Sean_soup]

I guess I should really practice rolling with a packed boat sometime…

That seems like a good idea. Not so much as a technical exercise (I think it's quite likely to actually be easier), but with rolling being such a head game mainly just to boost confidence so that you know you can.

Packing the boat securely seems like a good idea too - in the sense that things in the hatches aren't going to shift about. But in practice, is it even possible to pack a boat without cramming the hatches completely full? (Certainly doesn't seem to be in my case.) If you're particularly good at packing light I guess you could judiciously leave a little bit of air in your drybags so everything is a snug fit.

It's probably a good idea to practice paddling with a swamped cockpit too. (Not necessarily with a packed boat!) It's a really useful 'rough water' skill to be able to jump back in and paddle a short distance into an eddy, out of surf or whatever, to deal with emptying out the cockpit in calmer water later.

For day paddles with an unladen sea kayak, it surprises me a bit that it's so unusual for sea kayakers to use air bags. Lots of people carry repair kits and spare hatch covers, but having some air bags means that it's really not essential for a temporary repair in one of the hatches to be watertight. (Might even mean that a hole in the hull or a missing hatch cover doesn't need a temporary repair at all.)