Kayak Volume

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Dyllon
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Kayak Volume

Post by Dyllon » Fri Jan 20, 2017 5:45 pm

I am currently considering kayaks for a potential multi-week trip.

I currently have a Tiderace xplore S and feel that this is maybe a bit tight on storage for an extended trip although frequent inversions may also be a factor in looking for an alternative.

My preference is to have plenty of space to allow for an non-alpine approach to the trip and to avoid spending time every day utilising every last millilitre of available volume. However, after much perusal of manufacturer's specifications and the application of a degree of common sense, I have lost faith is such data.

I give you one comparison of manufacturer's data as an example:

Tiderace xplore s - Total volume - 330 L , Storage volume - 188 L (excluding deck pod/hatch);
Valley Etain 17.7- Total Volume - 366 L, Storage volume - 187 L (excluding deck pod/hatch).

Having examined and paddled both kayaks, I find it difficult to believe that both specifications are correct. Based on subjective consideration, I have a suspicion as to which data set is more correct; the Tiderace set. However, when I carry out similar comparison with other boats, I begin to have some doubts about the Tiderace data, e.g. does it really have 35 L more storage that a Northshore Atlantic.

This is more of a rant than a question. However, it would appear that the only way i can truly judge carrying capacity of a kayak is to take along a big pile of gear to each demo and see whether it can be accommodated. Any other ideas for evaluating true available storage would be welcomed. Also, feel free to point out if i am misusing the data in some way.

I am aware that I really should be testing boats with a full load, but one of may aims is to get a boat that is good for most of my paddling, which will be lightly loaded. So performance in this state is at least of equal importance.

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Re: Kayak Volume

Post by Fozzy » Fri Jan 20, 2017 7:24 pm

Take along a few drybags of known volume. Fill each compartment with water then empty (or pump) it into the dry bags and you have a relatively accurate volume for each one.
At the very least it will give you a good comparison.

Kaskazi
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Re: Kayak Volume

Post by Kaskazi » Fri Jan 20, 2017 11:29 pm

If you are looking for a high cargo volume sea kayak then I have a Kaskazi Skua you can try - been used on a multi week exped in Papau New Guinea by a well known 5* lady (can't mention her name) who gave it a sterling report. I'll try to find the volume for you, but it'll take 160kg easily.

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Re: Kayak Volume

Post by Owen » Sat Jan 21, 2017 11:35 am

Where are you going? Is this a multi-week wilderness trip where you will not be able to re-supply on route or is it around the coast of Britain?

What are you taking? A great many people can manage six month backpacking with a 50 - 60Lts rucksack, 188Lts should be luxury.

In the past I've managed some three week trips without the need for re-supply or freeze dry out of an old P&H Dawn treader and several two week trips out of a Northshore Atlantic.

For most sea kayaking 90% of the time you'll be doing day trips for the other 10% most of us just make do with what we've got. Seems a great expense to be buying a new kayak just for the odd long trip once or twice a year.

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Re: Kayak Volume

Post by Dyllon » Sat Jan 21, 2017 1:25 pm

Thanks all

It will be UK coastline. I don't want or need a huge boat for the very reason that Owen describes. 90% of my paddling will be day or weekend trips. However, I do utilise almost all of my current boat's capacity on weekend trips and fancied a bit more for the longer trip. I am just a bit frustrated in finding that I cannot rely on any data to support selection of a moderately larger boat.

An alternative approach might be to take less beer and use one of my current boats, but where is the fun in that?

Kaskazi - thanks for the offer, but as noted above, I am looking for something only a bit bigger than what I have available at the moment.

Fozzy - i had thought of that but don't believe that this would be any simpler than just taking a big pile of gear to each demo. Perhaps this is something the manufacturers should do to support their quoted figures.

Mark Graham
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Re: Kayak Volume

Post by Mark Graham » Sat Jan 21, 2017 3:08 pm

I suspect the unexpected difference in storage volumes (ie less or similar volume in a longer boat) could be down to the positioning of the bulkheads? If a longer boat has a longer internal length inside the cockpit then the length either side of the bulkheads will be compromised as a result, leading to it having the same or less 'storage' volume as a smaller boat as opposed to overall volume. But I suppose another factor is buoyancy, and therefore waterline, hull profile, windage etc with a heavy load, not just space.
I'm 5'10'' and there's quite a significant gap between my footrest position and the front bulkhead on my perception essence 16. I've never needed to use this space but it has crossed my mind to wedge a drybag in there if I ever needed to. There's also a bit of a gap behind the seat which will take a small dry bag etc, and one will clip nicely under the straps retaining the seat back. Its nice to have the extra legroom if I want to stretch my legs out during a break but it does mean that there's more space in the cockpit to fill with water and therefore more water to empty out making self rescues harder than they need to be.

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Re: Kayak Volume

Post by PeterG » Sun Jan 22, 2017 9:04 pm

The Anas acuta is not usually considered high volume but I had plenty of space for 2 months alone and unsupported hopping around the west of Scotland last summer. Resupply every couple of weeks was not a problem, plenty of mussels spins out the supplies, a mini kelly kettle does most of the cooking so I only used 2l of alcohol in the Trangia - a litre a month. There was always space to spare, although my trolley fits in the cockpit in front of my feet and replaces the footpegs -not an option for the long legged. I can honestly say I didn't want for anything.

The problem with a heavily laden boat is how to launch and land on often rocky shores. Every kilo saved increases the chances of a safe landing without damaging the boat or paddler.

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Re: Kayak Volume

Post by Dyllon » Mon Jan 23, 2017 5:31 pm

Two weeks, never mind two months, in an Anas Acuta sounds pretty impressive in my book. The Kelly Kettle sounds interesting and I will investigate further

However, and not wishing to detract from the above, according to the Valley website, the Anas Acuta has more storage capacity than a Nordkapp Forti, which is commonly described as an expedition boat. Take what you want from this. I have not paddled either or compared on the ground and, therefore, cannot comment on Valley's figures.

Having spent the afternoon playing with buckets of water, for the Tiderace xplore S figures to be correct there has to be a significant portion of volume above hatch level. In reality, I am not sure there is. One factor, which aligns with Mark's comments above is that the front bulkhead position could have changed at some time in the history of the design. In my boat it does seem very far forward for a boat designated with an 'S'.

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PeterG
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Re: Kayak Volume

Post by PeterG » Mon Jan 23, 2017 5:49 pm

http://www.mkettle.com/ re 'kelly' kettles this is then best one I've used.

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Re: Kayak Volume

Post by Chris Bolton » Mon Jan 23, 2017 9:13 pm

I think the volume figures for most boats vary in the way they're calculated, but volume isn't the only factor affecting how much you can fit in a boat, so even if you could rely on the volume data it wouldn't be sufficient. The shape of that volume is significant; how far from the hatch to the stern, how tapered and how high the space is, obstruction by skeg boxes and recessed deck fittings, etc. How you pack makes a big difference, smaller, tapered, soft drybags will enable you to pack far more than big rigid bags.

If you're going to be using the boat for 90% day trips, beware of having too much volume - you don't want a boat that's too high out of the water or it will be awkward to handle in a wind.

Irish Sea
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Re: Kayak Volume

Post by Irish Sea » Mon Jan 23, 2017 9:52 pm

Dyllon wrote:
However, and not wishing to detract from the above, according to the Valley website, the Anas Acuta has more storage capacity than a Nordkapp Forti, which is commonly described as an expedition boat. Take what you want from this. I have not paddled either or compared on the ground and, therefore, cannot comment on Valley's figures.
As somebody who has paddled an Anas Acuta for years and also owns a vintage Nordkapp HM which should be roughly comparable in size to the Forti I can guarantee that there's a very significant difference in volume between the two boats. Best guess: ~270-280l for the AA and ~330-340l for the Nordy. That's just a rough comparison based on other boats and their published volume figures. If you put the boats side by side you'll see that the Nordkapp is a hint wider, almost a foot longer and significantly higher in the deck, forward and in particular after.

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stormkayaker
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Re: Kayak Volume

Post by stormkayaker » Wed Jan 25, 2017 10:55 pm

Dyllon, we have most Tiderace models available for demo in South Devon.

PM me your details and we can sort out dates if you wanted to compare on and off the water.

Paul

Dyllon
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Re: Kayak Volume

Post by Dyllon » Thu Jan 26, 2017 8:27 am

Thanks Paul. That's something I plan to do and have made initial contact with the local Tiderace rep.

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JB-NL
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Re: Kayak Volume

Post by JB-NL » Fri Jan 27, 2017 4:32 pm

for comparison (for what it is worth) have a look:
http://www.kayakacrossthewater.co.uk/se ... son-chart/

Not sure how long you want to go, we went for a trip with 2 Nordkaps and an Orion, we carried 18 days of food and full equipment in each kayak, no stuff on the decks.
Was for a trip around the North coast of Iceland.

good luck,

JB
--==Never go faster than your Angel can fly==--

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dc9mm
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Re: Kayak Volume

Post by dc9mm » Sun Apr 16, 2017 9:14 pm

I just thought I would ad the front deck day hatch on tiderace boats is supposed to hold 6 liters on all models. It says so on there website. Total bull. I tried pouring water into that hatch and it took maybe just 3 liters filled to the brim. So I wonder if they lie about that hatch do they lie about the other hatch volumes?

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stormkayaker
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Re: Kayak Volume

Post by stormkayaker » Sun Apr 16, 2017 10:43 pm

Why not ask Dave Felton direct and post the reply so everyone knows?

df@tideraceseakayaks.co.uk

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Re: Kayak Volume

Post by Irish Sea » Mon Apr 17, 2017 8:05 am

dc9mm wrote:I just thought I would ad the front deck day hatch on tiderace boats is supposed to hold 6 liters on all models. It says so on there website. Total bull. I tried pouring water into that hatch and it took maybe just 3 liters filled to the brim. So I wonder if they lie about that hatch do they lie about the other hatch volumes?
The foredeck hatch is likely not part of the actual deck mould but is a "tub" that's glued to the underside of the deck later.
I'm speculating here but maybe it was made smaller at some point to increase room under the front deck and the stats not updated? Maybe the different manufacturers in Poland, Finland and now Thailand also used their own parts for this so it differs somewhat depending on who made the actual boat?

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Re: Kayak Volume

Post by Aled » Mon Apr 17, 2017 4:50 pm

Irish Sea wrote:I'm speculating here but maybe it was made smaller at some point to increase room under the front deck and the stats not updated?
Sounds right, the original larger tray was reduced in both height and length to create more shin clearance and foot room. The original could take flares, but the early models fitted with a full plate footrest were a pain to assemble.
One thing I can certify is that the total volume (front, cockpit, day and rear hatch combined - or total enclosed volume) for the Tiderace boats are accurate to my original CAD file data.

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dc9mm
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Re: Kayak Volume

Post by dc9mm » Wed Apr 19, 2017 4:14 am

Sounds like excuses to me. If it were just a little off say 5 liters In would say ok. BUT half of what is stated isn't even close. Plus then change the website if 6 liters is no longer correct.

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Re: Kayak Volume

Post by Irish Sea » Wed Apr 19, 2017 8:11 am

dc9mm wrote:Sounds like excuses to me. If it were just a little off say 5 liters In would say ok. BUT half of what is stated isn't even close. Plus then change the website if 6 liters is no longer correct.
Mistakes happen, somebody forgot to update the data on the website after some changes where made to the boat. A very small part of the boat that is. I honestly don't know why you are making such a big fuss about it. Seriously, would it have made any difference to your buying decision had you known that the front hatch is 3 litres smaller than advertised?

Dyllon
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Re: Kayak Volume

Post by Dyllon » Wed Apr 19, 2017 8:41 am

While I agree that the volume of a deck hatch is not likely to be a critical factor in choice of boat, it does highlight the issue that I raised in the first instance. If manufacturers cannot get this detail right in their boat data, what else are they getting wrong?

I suggest that if volume is of a concern when comparing boats from two different manufacturers, then you need to take a calibrated bucket with you when testing. In some cases, as highlighted above, one might need the bucket when looking at boats from the same manufacturer.

Tiderace changed to Thai manufacture in 2011 or so. Are you really suggesting that they have not had an opportunity to correct this since then? Some of their boats have only ever been made in Thailand.

R.

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Re: Kayak Volume

Post by MYSSAK » Wed Apr 19, 2017 9:05 am

Dyllon wrote: I suggest that if volume is of a concern when comparing boats from two different manufacturers, then you need to take a calibrated bucket with you when testing. In some cases, as highlighted above, one might need the bucket when looking at boats from the same manufacturer.
I agree it is nice to know actual figures like size and volume but even if those figures are accurate they still might be quite misleading. Shape of the boat is as important for packing and handling as is the volume.
I would rather spend time in the kayak paddling it (empty and loaded) to find out if it's right boat for me than running around with the bucket.

Michal

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Re: Kayak Volume

Post by Irish Sea » Wed Apr 19, 2017 9:19 am

Dyllon wrote:
Tiderace changed to Thai manufacture in 2011 or so. Are you really suggesting that they have not had an opportunity to correct this since then? Some of their boats have only ever been made in Thailand.

R.
I'm suggesting that somebody made an honest mistake forgetting about updating the datasheets after that relatively minor change was made - whenever that was.
A change, I may add, that didn't have any effect on the performance or the total volume of the boat.

On your other points I agree with you and it would indeed be nice if boat volumes where measured to the same standard everywhere and could be compared easily. Unfortunately that's not really the case. There are manufacturers out there that don't give volumes at all, many give only total volume, some have some very questionable volume figures, even when comparing their own boats.

In the end its about the fit of the boat and the performance with your planned weight on board so nothing replaces on the water testing.

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Jim
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Re: Kayak Volume

Post by Jim » Wed Apr 19, 2017 2:27 pm

Dyllon wrote:I suggest that if volume is of a concern when comparing boats from two different manufacturers, then you need to take a calibrated bucket with you when testing. In some cases, as highlighted above, one might need the bucket when looking at boats from the same manufacturer.
I would suggest you will never get the volume quoted.

If I were a kayak designer/manufacturer I would I calculate the volumes from the computer model, using what we call the moulded dimensions.

For a composite boat that is layed up to the inside of the moulded line, the interior volume will always be reduced by the shell thickness.
Once you add bulkheads, particularly those nice thick foam ones that avoid stress concentrations on the hull, than the exact location of the bulkhead, and whether the design moulded position is to the fwd side or aft side, or centreline of the bulkhead will all affect the actual volume of the tank you create.
Unless the manufacturer uses a jig to position bulkheads identically in every boat, there is always likely to be a few mm drift in bulkhead location so the exact volume of a compartment will vary a little from boat to boat.

For PE boats life is more complex because the PE boat will shrink around 3% on cooling before release from the mould, but the %age can vary. The volume quoted is probably adjusted to reflect the intended finished boat, but using a nominal shrinkage.

If you take the opportunity to have the forward bulkhead positioned to fit you as a footrest, or to minimise/maximise cockpit space beyond a foot rest, the volumes will not be as advertised.

Don't choose a boat entirely on the spec sheet, use the spec sheets to identify possible boats, and then try them all out and see which ones are best suited to the gear you want to carry. I don't even care what the volume of the Taran forward compartment is, all I know is that the depth is so great that I can get a tent packed normally with its poles in through the hatch, and i can get my thermarest normally rolled in its chair kit with poles in it also through the hatch, whilst in many boats there is not quite the space to do this without flexing the poles or removing them and posting them in one at a time. You will never get that detail from reading the spec sheet, but you will narrow down a range of boats to check out for real.

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dc9mm
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Re: Kayak Volume

Post by dc9mm » Thu Apr 20, 2017 4:25 am

I wasn't making a big deal out of it. I saw this post and recently picked up a Pace Tour 17 so I commented on the hatch that wasn't even close. I would have never started a thread about it I just added to this one since it was on the subject the OP started.

True it wouldn't have changed my mind on the boat had it said 3 liters. I just like accurate specs. I was looking at Valleys website and it shows that the new Sirona has more hatch volume that the etain even though the etain is a much longer boat. I emailed Valley they responded on were I got this info which I responded with a link on the OWN website. That was a month ago they never responded back. http://www.valleyseakayaks.com/options/compare-kayaks I thought it was strange a 16.1 foot boat would hold more than a 17.5 foot boat. Must be a much higher deck I guess?

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Re: Kayak Volume

Post by Irish Sea » Thu Apr 20, 2017 7:35 am

This Valley spec sheet has several very questionable volume figures, indeed. They also claim that the Anas Acuta has more volume than the Nordkapp 40 which is very interesting as the Nordkapp is a little wider, almost a foot longer and quite a bit higher in the deck than the AA. Historically the original Nordkapp was developed after test runs with the Anas Acuta where made and it was deemed too small and too slow for the planned expedition use. I own an oldish Nordkapp and have paddled the AA for years as my dayboat and there's no way they are even close in volume. Best guess: Nordkapp is 20% bigger-as an expedition boat should be when compared to a dayboat.

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Re: Kayak Volume

Post by Mac50L » Thu Apr 20, 2017 11:00 am

I see this started back in January.....
Question - anyone considered how much usable/accessible volume is lost due to the skeg box? My guess would be 2-5+ litres. The volume is there but you can't get a dry bag into it. One of the many (wait for it...) reasons to use a rudder?

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Re: Kayak Volume

Post by Jim » Thu Apr 20, 2017 12:05 pm

Mac50L wrote:I see this started back in January.....
Question - anyone considered how much usable/accessible volume is lost due to the skeg box? My guess would be 2-5+ litres. The volume is there but you can't get a dry bag into it. One of the many (wait for it...) reasons to use a rudder?
Technically the volume of the skeg box should be deducted from the boat volume since it is open to the sea and does not contribute to buoyancy.
Alternatively you can consider the boat to be permanently carrying extra weight (2-5kg if your guess is in the right area), but since this will depend on the waterline, i.e. how much you have loaded it up already, it is not very convenient.
In terms of stability calculations you get a slightly different result from lost buoyancy compared to added mass, but it is not relevant for a sea kayak.

More reasons to add to your list? :)

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