To the group: My question is. 1. a boat has so much displacement in fresh water does it have the same in salt water. 2. If this displacement is not the same then how do you know how much weight can the boat hold. If you get use to the boat in fresh water is it harder to get use to it in salt water. If you demo a boat in salt water will it feel slower in fresh water. Can you pack more in a boat that is going in salt water. I know that the specific weight is different then salt water than fresh water, is this a big difference or just in my mind *************************************************************************** PaddleWise Paddling Mailing List Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net Website: http://www.paddlewise.net/ ***************************************************************************
Steve James wrote: > My question is. 1. a boat has so much displacement in fresh water does > it have the same in salt water. 2. If this displacement is not the same > then how do you know how much weight can the boat hold. The difference is about 3% (sea water being about 3% more dense than fresh). If you know onedisplacement, you can calculate the other. Note: *in very round numbers,* if your kayak has a draft of 5.00 inches in salt water, it will have a draft of about 5.15 inches in fresh. The 0.15 inches is just a little over an eighth of an inch, and perhaps equivalent to the effect of adding (or removing) 10 - 15 lbs of cargo -- probably not noticeable in terms of performance, given that the paddler-boat system weighs something like 220 - 270 lbs, *when there is no other cargo in the yak.* Packed with 100 lbs of gear (and food and water) for a week-long trip, the all-up weight is 320 - 370 lbs, and the salt/fresh water difference is even less noticeable. > If you get use > to the boat in fresh water is it harder to get use to it in salt water. > If you demo a boat in salt water will it feel slower in fresh water. I doubt it. I've certainly never noticed any difference, fresh vs salt. > Can you pack more in a boat that is going in salt water. For an equivalent draft, yes: only about 10 - 15 lbs more, which amounts to only 1 -2 gallons of water. When I pack for an extended trip, I run out of volume in the yak long before I run out of cargo (weight-carrying) capacity. 'Course, my main long-haul boat is rated at something like 450 lbs(!). YMMV. -- Dave Kruger Astoria, OR *************************************************************************** PaddleWise Paddling Mailing List Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net Website: http://www.paddlewise.net/ ***************************************************************************
-----Original Message----- From: Steve James <sljames_at_pacifier.com> To: paddlewise <paddlewise_at_lists.intelenet.net> Date: Tuesday, September 21, 1999 2:22 AM Subject: [Paddlewise] weight of boats? >To the group: > >My question is. 1. a boat has so much displacement in fresh water does >it have the same in salt water. 2. If this displacement is not the same >then how do you know how much weight can the boat hold. If you get use >to the boat in fresh water is it harder to get use to it in salt water. >If you demo a boat in salt water will it feel slower in fresh water. Can >you pack more in a boat that is going in salt water. I know that the >specific weight is different then salt water than fresh water, is this a >big difference or just in my mind The displacement remains the same. The boat just floats lower in fresh water. If you get the chance to look at a ship you will see a set of odd looking lines on the side near the waterline. These are called Plimsoll lines after the fellow who championed the safety of sailors. The lines are supposed to prevent overloading and were established as law by the British in the Nineteenth century. I don't recall what each line means anymore but I think there were lines for Tropical salt, Tropical fresh, North Atlantic, Fresh and Pacific. Probably all wrong as my memory is fading. Salt water is often taken as 64 pounds per cubic foot and fresh as 62.3. This is not iron clad as the practice varies between countries, designers, the temperature the density is taken at and etc. On one of my designs the boat floats 5/64" deeper in fresh water than in salt water (using the above figures). Cheers, John Winters Redwing Designs Web site address, http://home.ican.net/~735769 *************************************************************************** PaddleWise Paddling Mailing List Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net Website: http://www.paddlewise.net/ ***************************************************************************
735769 wrote: > > looking lines on the side near the waterline. These are called Plimsoll > lines after the fellow who championed the safety of sailors. The lines are > supposed to prevent overloading and were established as law by the British > in the Nineteenth century. I don't recall what each line means anymore but I > think there were lines for Tropical salt, Tropical fresh, North Atlantic, > Fresh and Pacific. Probably all wrong as my memory is fading. My memory is like yours, i.e. those sound about right and mine is fading as well. I also thought there was a line for North Atlantic winter, on the supposition that the waters are stormier in winter (I suspect it was in an subconscious display of modesty that John Winters overlooked a line that would represent his name :-)). It would be so easy to check in some book or by paddling alongside some freighter. All the lines represent a level to which the commercial vessel can "safely" be loaded. ralph diaz -- ----------------------------------------------------------------------- Ralph Diaz . . . Folding Kayaker newsletter PO Box 0754, New York, NY 10024 Tel: 212-724-5069; E-mail: rdiaz_at_ix.netcom.com "Where's your sea kayak?"----"It's in the bag." ----------------------------------------------------------------------- *************************************************************************** PaddleWise Paddling Mailing List Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net Website: http://www.paddlewise.net/ ***************************************************************************
735769 wrote: > > Salt water is often taken as 64 pounds per cubic foot and fresh as 62.3. > > On one of my designs the boat floats 5/64" deeper in fresh water than in > salt water (using the above figures). > Yes, yes, well and good, but how much does the waterline length change? ;) Steve *************************************************************************** PaddleWise Paddling Mailing List Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net Website: http://www.paddlewise.net/ ***************************************************************************
Interesting: In pre MTV South Africa and also possibly in England, boat shoes and or sneakers were referred to as Plimsolls. -----Original Message----- From: owner-paddlewise_at_lists.intelenet.net [mailto:owner-paddlewise_at_lists.intelenet.net] On Behalf Of rdiaz_at_ix.netcom.com Sent: Tuesday, September 21, 1999 12:50 PM To: 735769 Cc: paddlewise Subject: Re: [Paddlewise] weight of boats? 735769 wrote: > > looking lines on the side near the waterline. These are called Plimsoll > lines after the fellow who championed the safety of sailors. The lines are > supposed to prevent overloading and were established as law by the British > in the Nineteenth century. I don't recall what each line means anymore but I > think there were lines for Tropical salt, Tropical fresh, North Atlantic, > Fresh and Pacific. Probably all wrong as my memory is fading. My memory is like yours, i.e. those sound about right and mine is fading as well. I also thought there was a line for North Atlantic winter, on the supposition that the waters are stormier in winter (I suspect it was in an subconscious display of modesty that John Winters overlooked a line that would represent his name :-)). It would be so easy to check in some book or by paddling alongside some freighter. All the lines represent a level to which the commercial vessel can "safely" be loaded. ralph diaz -- ----------------------------------------------------------------------- Ralph Diaz . . . Folding Kayaker newsletter PO Box 0754, New York, NY 10024 Tel: 212-724-5069; E-mail: rdiaz_at_ix.netcom.com "Where's your sea kayak?"----"It's in the bag." ----------------------------------------------------------------------- *************************************************************************** PaddleWise Paddling Mailing List Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net Website: http://www.paddlewise.net/ *************************************************************************** *************************************************************************** PaddleWise Paddling Mailing List Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net Website: http://www.paddlewise.net/ ***************************************************************************
-----Original Message----- From: Steve Cramer <cramer_at_coe.uga.edu> To: Paddlewise <paddlewise_at_lists.intelenet.net> Date: Tuesday, September 21, 1999 11:58 AM Subject: Re: [Paddlewise] weight of boats? >735769 wrote: >> >> Salt water is often taken as 64 pounds per cubic foot and fresh as 62.3. >> >> On one of my designs the boat floats 5/64" deeper in fresh water than in >> salt water (using the above figures). >> >Yes, yes, well and good, but how much does the waterline length change? >;) > Hardly at all on boats with short overhangs but then, they start out longer anyway. ;-) Cheers, John Winters Redwing Designs Web site address, http://home.ican.net/~735769 *************************************************************************** PaddleWise Paddling Mailing List Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net Website: http://www.paddlewise.net/ ***************************************************************************
Mr. John Winters said, "Hardly at all on boats with short overhangs but then, they start out longer anyway.;-" And on behalf of all the boys with short overhangs I would like to thank him and state that it is true, we do stay out longer. And furthermore ......What.. I misread his post? Excuse me, my wife is reading over my shoulder again.... Oh my....Please, disregard the previous few forgettable lines.. This has been a test. We now conclude our test of the PW Anal Retentive Detection and Extermination Test. If you are still reading this post you; A.You are not now or are ever likely to suffer from this dreaded affliction. B.Are fully purged of your peg and shall go forth and retent no more. ...... OR...... C.Are so Anal Retentive that you have sucked yourself inside out and are now the exact opposite of yourself.. Disclaimer... The above few lines do not necessarily reflect the views and or opinions of me or anyone that I know now or ever may know in the future. My name is Bruce WEO *************************************************************************** PaddleWise Paddling Mailing List Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net Website: http://www.paddlewise.net/ ***************************************************************************
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