Wave Piercing Exposed
I once did a post explaining the Wave Piercing concept, many said they could understand how it works after reading it, but if you still don´t get it, just look at this video above. I think is the best filmed proof of the efficiency of this concept. Thus the title of the post. Bouncing vs forward drive and speed (check 1:30), not only on the rake but on the volume distribution, check Wave Piercing Explained for more details.
My brother build kayaks and he wants me to design one for him, after checking what he showed me I told they all look ‘antique’, and that I was going to draw a wave piercer. Searching if someone already made one I found a Swede design by Magnus de Brito Point 65 Bourbon Orca. Name inspired on the boat in the video.
It was funny to see how they use the Wildcat as reference See picture to the left made by GlobalSurf Ski blog. And like beachcats the Surf Ski designs will end in this shape for sure, as they are use for racing in open waters too and even launch and surf back to the coast.
Already have some lines I started yesterday, I will do some research and maybe some CFD. Magnus design looks really good and it seems is working great. He also designed a clever two parts modular kayak. Check Magnus work at www.debrito.se
Images GlobalSurfSki
https://carbonicboats.blogspot.com.au/2012/07/we-are-receiving-many-questions-about.html
You got it completely wrong: The bow of the Bourbon Orca has 900 m³ more volume than a conventional offshore support vessel, the idea behind it being, that the vessel will immediately start rising the bow, when entering a wave.
So the idea behind it is the complete opposite of the BS the cat builders are telling you.
Furthermore, the conventional vessel is 2 m shorter, 2 m wider, has 25% more displacement and about half the power. Not comparable in any way.
The Bourbin + wildcat does not geometrically equal the debrito. The case for reversed bows is moving towards them being fashion vs function. 1) Originally they were reversed because the sectional bow shape was a pear which mean't the hull ran out of geometry at its top. The pear shape comes from the requirement to increase Cp but allow water shedding and inhibit ploughing when the bow goes under. 2) Current designs are returning to a vertical fwd (albeit a small vertical then a reverse. 3) We do need to adopt something like the Bourbon bow however as a bladed or sharp leading edge produces considerable drag as it creates a vortice. This is becuase sail boats have leeway so the sharp edge never points into the flow. A rounded leading edge allows the flow to adapt to the leeway, just like correctly designed foils do. We don't make foils with sharp leading edges do we! The idea of a sharp edge cutting through the water is incorrect. We actually need bows that go "over" the water rather then "through" it. Cheers Peter S
I think both of you guys are letting "Wave Piercing" block your minds…
And you are not reading anything else of what is written and linked in this post or on the 'Wave Piercing Explained' link.
The Bourbon Orca vs the other vessel is a good comparison between two different antagonic concepts beyond size.
If the the other vessel would have the same m2 of volume , that would not change the key factor of its different distribution, clearly the main functional concept of modern 'WP'.
"Wave Piercer" it is just the name that remains from early reverse bow concepts.
So it seems you don´t know much about modern racing cats, as the concept is similar to what you describe and has nothing to do with early thin bow 'wave piercers'.
Just ride & compare a Tiger vs an Infusion/Falcon/Phantom and you'll get the picture in the chop.
Peter: The Bourbon + Wildcat was made by the Surf Ski guys….
Read the WP Explained too.
I'm making reference and linking to the original GlobalSurfski article.
I just like the video that took it from there…
Hi CSN, I'm fully aware of all the technical issues discussed and whats on the water. I know what a "wave piecer" is. Its good to look at surf skis for instance to see what they do but surf skies don't have leeway which does affect the leading edge design of hulls. I made a series of technical points not a personal attack. Cheers Peter S
You can say whatever you want on technical aspects.
I'm just pointing out that your are making a 'doctoral' analysis of a composed image made by another website.
On the links, is not for you to learn, as it seems you know plenty.
But on the concept on how I understand wave piercers, that has nothing to do with your implications derived from an image taken from a Surfski website. Clearly pointed out on the post.
Bottom line: The relation made on the Bourbon Orca vessel + Wildcat was not mine, I posted it as I like how they also look up to F18s for their concept.
You should make some comments there, but take it easy… Magnus seems to know 1 or two things too.
Cheers,
Martin