Colas.Nahaboo.net - sup

10 minutes full SUP and Surf Warmup video, v9

2026-04-22T00:00:00+00:00

This is my 10 minutes warmup routine before my morning SUP session, version 8. Follow-along, 10 minutes exactly, no intro/outro.

https://youtu.be/4FUwYA6NgWs</a>

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Altough I insist on things important for SUPing (calves, trunk twists, burpees) it can be used as a warmup routine for all uses. No commentary nor music track as I do not want to wake up the house on my dawn patrols :-) Add yours if you want to.

As I am 65 yo, and I SUP/surf very early to avoid crowds, I need a full 10 minutes warmup to avoid injuries. I thus do it at home just before driving to the beach, otherwise I could not discipline myself to do it on the beach. If you are younger, or before an afternoon session, just play the video at 2x speed for a 5mn quicker warmup :-)

This 10-minute warmup video provides a series of 30-second exercises designed to activate the muscles and joints. The goal is to lubricate the joints, to warm up, not to reach maximum flexibility. Avoid pushing into full stretches. Use furniture for support if needed to ensure a safe range of motion.

It is a compilation of 30 seconds sections, copied from the Youtube warmup videos below (in order of appearance). Refer to them for details and explanations.

Calves: https://www.youtube.com/watch?v=7Zs4hh4cp98</a>

Lunges front: https://www.youtube.com/watch?v=79yebGL3NX0</a>

Ankles: https://www.youtube.com/watch?v=kRwSyXzVtNk</a>

Trunk Twists: https://www.youtube.com/watch?v=LqdvhvePVFU</a>

Full Body: https://www.youtube.com/watch?v=VecbXgWY0DI</a>

Hip rotations: https://www.womenshealthmag.com/fitness/g26554730/best-warm-up-exercises/</a>

Lunge Twists: https://www.youtube.com/watch?v=6jy4HYOhRmI</a>

Burpees: https://www.youtube.com/watch?v=yewKJShD1EU</a>

New in this v9:

The countdown timers were missing in all sections!</li>

This v9 replaces the v8 version at: https://youtu.be/Bwe6kBA-sPc</li> </ul>

Mastering lateral balance on a small SUP board

2026-03-25T00:00:00+00:00

After some experiments, I think I have found an easy way to have a good lateral balance on a small board. A small board being one with little lateral stability, be it because it is narrow, have thin rails, low volume, ...

Your front foot must be parallel to the stringer, and:

the less the board is stable laterally, the less distance it must have from the stringer.

The back foot will naturally position itself symmetrically wrt the stringer, so you actually only have to focus on the front foot.

To find this magic position, look at the following diagram:

top row: if your feet are too close together, when you lean on one side, the leverage on the board will be not strong enough to make it roll at the same angle as your body: you feel the urge to widen your stance to keep balance</li>
middle row: if your feet are too wide apart (the problem of most people), when you lean on one side, the leverage on the board will make it roll faster than your body and you will be thrown overboard and your low foot will slip.</li>

bottom row: the perfect position: you will wobble as if your board and you was a solid culbuto toy. You want to be one with your board, as for banking in turns on a bike. Balance suddenly becomes super natural and smooth. It still needs a lot of concentration and it is still tiring, but it is definitively easier.</li> </ul>

And once you experience this feeling, it is easy to re-find this perfect foot position by feeling how your board react to your wobbles. It will not feel natural at all at first, but you must resist the urge to widen your stance, you will get quickly used to it.
It is especially useful if your rails are underwater. If your board has too much volume, it will not roll smoothly on its side (it resistance to rolling will vary with the angle), and the foot position is less critical. But for small and/or narrow boards, it is a very convenient rule of thumb to find the quickest way to feel at ease.
In practice this means that your feet are quite close to the stringer:

The semi surf stance (front foot aligned with the stringer, rear foot slightly open) is mandatory on small boards, both for paddling balance and early take offs, as I often stress.

By having the front foot parallel to the stringer there is no difference in lateral balance when your weight moves between your toes and your heel, something that happens a lot unconsciously as you keep your balance. In my experience having your heel closer to the rail than your toes is the recipe for unexpected disaster.
When I advise people I even make it a mandatory condition to get on boards shorter than 8'. You will not benefit from a short board if you do not want to force yourself to stop paddling with parallel feet. A surprising number of people keep paddling parallel on small boards and thus take off really late and miss a lot of waves, or take off too late and a get the wave close on them.
I made a dedicated post for the lateral balance issue because at 59 [at the time I wrote this post], after 10 years SUPing, I felt that the lateral balance was the main thing what I felt worse than when I was younger: I am slower to react. I was thinking that (relatively) narrow boards were not for me anymore. Younger people will be able to put their feet about anywhere, but for most people, I think looking for this lateral balance point will be very useful, as the board moving with you let you more time to react before things need correcting.
This post was originally made at seabreeze</a> on 2019-04-02. You can read the discussions it generated there.

Wetsuits chest zip direction: reverse!

2026-03-24T00:00:00+00:00

I used to buy mostly Rip Curl wetsuit, and when they decided to reverse the chest zips, I was puzzled, but after the first session, I was convinced:
Chest zippers must open towards the inside

Normal direction: Bad!</figcaption> </figure> </label> </div>

Reverse direction: Good!</figcaption> </figure> </label> </div> </div>
Why?

Reduced stress: The natural tension on the wetsuit doesn't pull the zipper open. This eliminates the need for a cumbersome stopper or a snap button, as it cannot come undone on its own in the water.</li>
Greater range of motion: The "inside" end of the zip is free from the bulk of the starting mechanism, allowing for a wider opening. This makes getting in and out of the suit noticeably easier.</li>
Durability: The stress of entry and exit is concentrated at the "open" end of the zipper, where it is less likely to cause damage.</li> </ul>
The picture on the right is of my Feral wetsuit. It’s an excellent Yamamoto neoprene suit, but it is cut a bit smaller in the chest than other brands. Because of this, I actually blew out the zipper during only my second session—something that has never happened to me before.
I had it reversed by a local repair shop (the excellent All-In repairs</a>), and the difference is staggering. The wetsuit feels noticeably looser and more comfortable in the chest!
My advice:

Prioritize wetsuits with reverse zippers.</li>
Standard zippers can be reversed by your local wetsuit repair specialist.</li> </ul>

Repairing a broken leash on the water

2020-12-28T00:00:00+00:00

I have found a simple to do and easy to remember method to repair a broken leash cord on the water. Just grab the broken bits parallel in the hand and do a simple overhand bend knot, one of the simplest knots around. The trick is just to pull the knot really, really tight hard before resuming the surfing session.
Of course this not a permanent repair, as the knot will add drag to the leash, but it is enough to finish the session securely.
Image courtesy of netknots:

See the full animation at netknots</a>
Here is the result on a leash broken leash during my session:



Note: I first posted this article on seabreeze</a> </blockquote>

The Donaldson trailing edge, no more fin hum!

2020-07-07T00:00:00+00:00

At last, I have found a good video explaining how to suppress the vibration of fins and foils, and giving the name of this technique : the Donaldson trailing edge, described in 1956 by ... Donaldson
Up to now, I had only seen the diagrams for symmetrical foils (just sand only one side, not both) but this video goes into the details and show that you must sand the inner face of asymmetrical foil (flat one), not the curved one.
Thanks to Mario Legenstein from Levitaz for the video: </iframe>
I thus also learned that the effect causing the humming is "Vortex Shedding", aka the "Von Kármán effect</a>". On thick trailing edges, vortexes are created alternatively on the two sides of the trailing edge, and they push and pull on it at a frequency depending of the speed and the edge geometry. These alternating forces make the foil or fin vibrate and hum.
You can google "Donaldson trailing edge" to find many detailed references. For instance:
Boundary layer effects on the vortex shedding in a Donaldson-type hydrofoil</a>
Vortex shedding from blunt and oblique trailing edge hydrofoils</a>
And these wind tinnel images show the alternating vortexes creating the vibrations on a blunt edge on the left, and how the Donaldson edge locks the vortex in place on the right:
Here is a comparison of the amount of vibrations for different shapes of the trailing edge:
This von Kármán effect is what makes ropes whistle in the wind, can destroy underwater pipelines, and can destroy bridges when they vibrate in sync with the wind, such as the famous Tacoma bridge: https://aerospaceengineeringblog.com/the-von-karman-vortex-street-and-tacoma-narrows-disaster/</a>
Spiral ridges are added to chimneys to prevent the effect: https://web.archive.org/web/20190824084241/https://spartaengineering.com/vortex-shedding-and-tall-structures/</a>
And it happens also at wide scale, and can be seen from space:

https://earthsky.org/earth/these-are-von-karman-vortices</a></li>
https://earthobservatory.nasa.gov/images/90734/two-views-of-von-karman-vortices</a></li>
https://oceancolor.gsfc.nasa.gov/outreach/ocsciencefocus/VariousViewsofvonKarmanVortices_o.pdf</a></li> </ul>

Note: I first posted this article on: https://www.seabreeze.com.au/forums/Stand-Up-Paddle/SUP/The-definitive-solution-to-fins-and-foils-whistling-humming--The--Donaldson-trailing-edge-\</a> </blockquote>