• 30th August 2015 - By greg


    I thought I answered this question back in 2008 when I travelled 245 km in 24 hours on Whitefish Lake setting a world record for the most distance by human power on flat water beating Carter Johnston’s kayak record by a mere 3 km.

    In 2013, Brandon Nelson bettered Carter’s kayak record by paddling 244.4 km in 24 hours, but just failed to meet my benchmark of 245. Then in 2014, Carter and I staged a 24 hour race on Whitefish Lake hoping for a new record from one of us, but mother nature had other plans. Bad weather prevented a 24 hour attempt, so we shortened the race to a 12 hour event in rough water conditions with Carter beating me, and setting an unofficial 12 hour distance record in the process.

    Shortly after our 12 hour race, Carter broke Brandon’s 24 hour kayak record on a course in Huntington Beach, CA, traveling 249 km in 24 hours and breaking my 2008 record in the process.

    The ball is back in my court.

    I’ll be turning 55 years old this year and I was 47 when I set the record back in 2008. The only way to break Carters 249 km distance record is to design a faster boat. I would hope that my own fitness is still adequate for the job – possibly even better since I have put thousands of miles on these legs since 2008. But I can’t bank on that. I need to get back to the drawing board and shave some serious weight off of Critical Power 2 – my 24 hour record boat from 2008. She has gained quite a bit of weight since then:

    2007 kayak based pedal power. 8 kph. heavy and slow

    2007 kayak based pedal power. 8 kph. heavy and slow

    2008 CP2 first test probably 45 lbs

    2008 CP2 first test 51 lbs

    2008 CP2 Word Record 41.5 lbs

    2008 CP2 Word Record 41.5 lbs

    CP2 2013 for Pedal vs Paddle race probably 45 lbs

    2013 CP2 for Pedal vs Paddle race probably 45 lbs

    CP2 2014 for MR340 60 lbs

    2014 CP2 for MR340 60 lbs

    2015 Special K MR340 101 lbs

    2015 Special K MR340 101 lbs


    It will take a brand new boat that weighs in at no more than 27 pounds! And that won’t be easy!

    Those who have followed my exploits over the years know that the genius behind these brilliant designs is my engineer friend Rick Willoughby from Australia. He and I are hard at work trying to figure out how to accomplish this. Using Ricks speed calculator spreadsheet, here is how I came up with a minimum design weight of 27 pounds for the new boat:

    I took my 2008 record distance of 245 km and calculated an average speed of 10.26 kph over the 24 hours. According to the speed calculator, and a total weight of 191.58 lbs for the record boat, that meant that I must have averaged only 90 watts for the entire 24 hours. I was quite shocked to figure that out because my power goal was 150 watts which I probably averaged for the first 12 hours, and with periodic slow downs, stops to remove weeds, etc, that probably down-averaged to 130. Then the last 12 hours I know I slowed quite a bit – maybe even below 100 watts considering slow-downs, etc. But… I’m quite surprised at the puny 90 watt average.

    ASSUMING that I can repeat what I did 7 years ago, and maintain an average of 90 watts using the target weight for the new boat at 177 lbs (150 lbs worth of me + 27 lbs worth of new boat), I should be able to maintain 10.68 kph resulting in 256.3 km in 24 hours, beating my old record by 10.68 km.

    So how do we build a boat that weighs only 27 lbs?

    We start with one of the best composites men I know – Yancy Scroggins from Kansas City, MO, and add one of Rick’s killer new flat panel hull designs. Special K was a flat panel boat as opposed to CP2’s rounded hull. Why flat panel? Well, according to the calculations (backed up by real-world testing), the flat panel boat is equally as fast as a “U” shaped hull considering the total displacement, but the flat panel can be constructed much lighter – which, would make it faster. Yancy thinks he can build the main hull for me and come in at 15 pounds! That’s huge. well, no – it’s small, but small is good, so it’s huge. Estimating weight for the stabilizers, seat, pedals, shaft, prop, etc, I come up with 12 pounds. 12 + 15 = 27 lbs total.

    But I think I can do better. Knowing that my actual power output for the entire 24 hour record in 2008 was only 90 watts, I’m pretty sure I could do a better job of managing that power output by starting and finishing at around the same level rather than completing the first 12 hours in a faster than target time. Averaging 100 watts for the entire 24 hours sounds ridiculously easy – if it was managed correctly by STICKING to 100 watts, NON-STOP all the way through 24 hours. Here are the power output / distance projections:

    Power watts – Speed kph – 24 hr Distance ( current record = 249 km Carter Johnson )

    90 watts – 10.68 kph – 256 km
    100 watts – 11.05 kph – 265 km
    110 watts – 11.41 kph – 274 km
    115 watts – 11.58 kph – 278 km
    120 watts – 11.75 kph – 282 km

    Other potential gains

    There is another area that Rick and I are working on that may add some efficiency to the new design: Hydro foils. I’ve been testing a couple of small foils to see if the drag caused from the foil is less than the displacement reduction. Or at the very least, we are trying to get a couple of foils to lift the stabilizer floats (outriggers) up and out of the water so that the boat is balanced on the main hull by the foils rather than the stabilizer floats dragging through the water. I’ll details my experiments with foils in a future blog post.

    And now that Helen is a seasoned recumbent human powered boater, I want to encourage her to take a crack at the women’s 24 hour distance record of 201.2 km by Anjeanine Lees (Australia) at Burley Griffin Canoe Club, Canberra, Australia, on 6-7 December 2014. (I’m not too sure Helen’s interested and frankly I don’t really blame her 🙂 )

  • One Response to “how far can 1 man go in 1 day?”

    • James Murphy on December 10, 2020

      go with the hydrofoils, you will gain speed using the same power requirement.

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