Chris G Hardenbrook wrote: <SNIP> > And now, is there a formula for computing kayak volume? Since the hull & deck shape of kayaks vary dramatically between different models, a "formula" that fits all might be a little hard to come by. Offhand, I can think of four methods: 1) Easiest solution would be to call the manufacturer for design specifications. 2) Another method is to load the boat with something of known density & then weigh the boat before & after. Let's say your empty boat weight 42 lbs. Your boat filled with fresh water weighs 805 lbs. (805 - 42) / 7.48 = 102 gallons. (Fresh water weighs 7.48 pounds per gallon). So your volume is 102 gallons. While theoretically correct, it might be difficult to weigh 800 pounds of water-loaded kayak on the typical bathroom scale. :-) 3) Approximate method. Turn a garden hose on and measure the time it takes to fill a 5 gallon bucket. Do it again and take the average of the two times. Now fill up your empty kayak with water and measure the time it takes to do so - taking care to evenly distribute the water on both sides of bulkheads as you go. (A bulkhead could fail if it has a lot of water pressure on one side, and only air on the other). You might want to do this while floating the boat to equalize the pressure inside & outside of the hull. When the boat is full of water, check your watch again and note the time it took to fill up the boat. Let's say it took 3 minutes 15 seconds (3.25 minutes) to fill the 5 gallon bucket and it took 1 hr 10 minutes and 10 seconds (70.2 minutes) to fill the boat. Then your boat's volume is 70.2 X (5 / 3.25) = 108 gallons. I'm aware there's a rounding error here, but the accuracy of the bucket-filling test is such that our results are limited to 3 figures. 4) The Archimedes Principle states that the buoyancy force exerted on an object immersed in a fluid is equal to the weight of the fluid (WATER, in our case) displaced. So float your boat in a shallow sandy area, and fill it with rocks until it sinks. Now take all the rocks out & weigh them. Divide the total weight of all the rocks by 7.48 and you'll have the boat's volumetric capacity, in gallons. OK, OK. I can hear you chuckling! I *said* it would be easier to just call the manufacturer. But for those of us with a scientific inclination, and some time to spare, these little experiments can be illuminating, as well as amusing! Although - I confess I've never sunk my boat with rocks! Craig Olson Bellingham, Washington *************************************************************************** PaddleWise Paddling Mailing List Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net ***************************************************************************
Craig Olson wrote: > 4) The Archimedes Principle states that the buoyancy force exerted on an object > immersed in a fluid is equal to the weight of the fluid (WATER, in our case) > displaced. So float your boat in a shallow sandy area, and fill it with rocks until > it sinks. Now take all the rocks out & weigh them. Divide the total weight of all > the rocks by 7.48 and you'll have the boat's volumetric capacity, in gallons. > ... for those of us with a scientific inclination, and some time to > spare, these little experiments can be illuminating, as well as amusing! Although - > I confess I've never sunk my boat with rocks! Well, Craig, I seem to recall that you came pretty close to applying this method on a certain coastal trip last summer (although you were using gear instead of rocks). :-) At least now I know what you were tying to do. Next time I will help you out by letting you carry some of my denser items. Dan Hagen *************************************************************************** PaddleWise Paddling Mailing List Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net ***************************************************************************
Dan Hagen wrote: > Craig Olson wrote: > > > 4) The Archimedes Principle states that the buoyancy force exerted on an object > > immersed in a fluid is equal to the weight of the fluid (WATER, in our case) > > displaced. So float your boat in a shallow sandy area, and fill it with rocks until > > it sinks. Now take all the rocks out & weigh them. Divide the total weight of all > > the rocks by 7.48 and you'll have the boat's volumetric capacity, in gallons. > > ... for those of us with a scientific inclination, and some time to > > spare, these little experiments can be illuminating, as well as amusing! Although - > > I confess I've never sunk my boat with rocks! > > Well, Craig, I seem to recall that you came pretty close to applying > this method on a certain coastal trip last summer (although you were > using gear instead of rocks). :-) At least now I know what you were > tying to do. Next time I will help you out by letting you carry some of > my denser items. Say, Dan. Are you by chance referring to a certain rough-water ocean-swell & small-craft advisory wind-wave trip around K***y Point? As I recall, *You* went out first just to "check things out" and didn't respond on the VHF for over 15 minutes. My land-lubbing partner & I naturally assumed you'd encountered the worst, so I went out to rescue you. Far from trying out some 3rd century BCE (Before Common Era) Greek scientist's buoyancy theory, I was merely trying to make sure you had not met a bad end on the high seas. If you are in need of assistance in transporting your gear, perhaps you could contact a ferry service? Craig Olson Bellingham, Washington *************************************************************************** PaddleWise Paddling Mailing List Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net ***************************************************************************
Craig Olson wrote: > Say, Dan. Are you by chance referring to a certain rough-water ocean-swell & > small-craft advisory wind-wave trip around K***y Point? As I recall, *You* went out > first just to "check things out" and didn't respond on the VHF for over 15 minutes. I was having too much fun. :-) > My land-lubbing partner & I naturally assumed you'd encountered the worst, so I went > out to rescue you. Far from trying out some 3rd century BCE (Before Common Era) > Greek scientist's buoyancy theory, I was merely trying to make sure you had not met > a bad end on the high seas. You should know better. I am on great terms with all the requisite sea nymphs. BTW, to "rescue" me you first would have to find me! It's a good thing for me that I didn't need rescuing. (That was a nice little gale, wasn't it?) > If you are in need of assistance in transporting your > gear, perhaps you could contact a ferry service? Gee, do I detect a touch of hostility? And to think that I was just trying to help you out with your experiment! You should add to your list of techniques for measuring volumetric displacement the use of a computer program--this is how Sea Kayaker magazine does it. They take some measurements, plug them into a computer program, and out comes a volume estimate. Dan Hagen *************************************************************************** PaddleWise Paddling Mailing List Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net ***************************************************************************
Dan Hagen wrote: > I was having too much fun. :-) > > > My land-lubbing partner & I naturally assumed you'd encountered the worst <SNIP> > You should know better. I am on great terms with all the requisite sea > nymphs. BTW, to "rescue" me you first would have to find me! It's a > good thing for me that I didn't need rescuing. (That was a nice little > gale, wasn't it?) Quite true. It seems likely that you and I were within 100 yards or less of each other, but could not see each other because of heavy swell and because we were both concentrating hard on staying afloat, without a lot of time to look around. > > If you are in need of assistance in transporting your > > gear, perhaps you could contact a ferry service? > Gee, do I detect a touch of hostility? And to think that I was just > trying to help you out with your experiment! No, no - no hostility at all! I was merely trying to suggest a possible solution. A simple observation of your obviously overloaded craft! :-) > You should add to your list of techniques for measuring volumetric > displacement the use of a computer program--this is how Sea Kayaker > magazine does it. They take some measurements, plug them into a > computer program, and out comes a volume estimate. Oh dear! Adding *that* method to my list would require some actual *research* - which is more than this cowboy bargained for when he signed onto this kayak dude ranch! Paddle on! Craig Olson Bellingham, Washington *************************************************************************** PaddleWise Paddling Mailing List Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net ***************************************************************************
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