Almost done w/ my small fish project (some pics to be posted soonish w/ test ride report) and already obssesing about a semi-hullish bigger than a fish all around something or other.
Been reading archives steadily. Often see for both fish and hulls “I used X” nose rocker and Y" tail rocker but never any description of distribution. I know, at least traditionl fish have progressive rocker going to total flat just as you hit the tips of the tail, so a lot of the board is pretty flat.
Anderson Pescado`has “fish rocker” according to his site and also claims it is more user friendly than true hull. Is this something to do with fish rocker vs hull rocker or more because is has lower profile hull and thruster cluster finnage?
Looking at profile shots, hard to tell difference between fish rocker and hull rocker. Both look pretty flat towards tail and more curve in nose. What is the difference?
Also looking at surfblanks america blanks they have 3 fish/egg blanks 6’2" to 7’2" that have same rocker at the tips which means the longer the flatter the whole blank. Seems counter intuitive to me. What’s up with that?
Anybody feeling charitable and like riffing on these questions, I’d be most grateful.
yo dr s a years or twos agos i once had the idea of synthesisizing a hull with a fish and so butchered a 6-2 c into a 5-10 x 21.5 x s-deckage nice fairly traditional (for a 5-10 at least) outline wide pt a bit forward
nice even moderate entry rocker to about midboard, little to NO tail rocker out back.
1/2 hull depth up front flowing to rear thirds doub conc
super pinched railed, that were so knifey, even up front, the thing hated any chop
FAST down the line.
CRAPPY in terms of recovering from lip bashes or fast direction changes.
To be expected of a board with little tail rocker.
hope helps some not all times
i say gets rough rocka measurements of each design yous like and split the difference
I’m going for thicker rails, slightly egged only and round for small to med surf. Very low profile MellowVello type hullishness but I think rocker is a big key to performace characteristice (as so many variables are) and so the initial question of
What is the difference between hull rocker and fish rocker (stemming in part from reading about the Pescado and several very favorable reviews of the ride by forum members). All the hulls I’ve had (long ago and far away) had totall flat rocker in tail. Some had only 4-6 inches dead flat behind deepish vee that was mostly in front of fin. Very thin rails w/ belly in nose and 50/50 thin round rails to tucked razor edge on a round rail in back. One only had any bottom curve from wide point forward. That one basically didn’t really do cutbacks but was screaching blue blazes fast down the line (18 1/2 inches wide) Not really a true hull that one, chine bottom w/ big single concave between the chines w/ slightly egged rails.
Sooooo, what is the difference in distribution of curves between hull rocker and fish rocker?
First off…there’s no law that the rocker should be one thing or another for a given design. Its just a tool to get the board to perform in a given way.
The hulls I’ve ridden and attempted to shape have more of a lift than a curve in the last half of the board. Kind of straight segments with blended transitions. For a 7’+ board I see around 1.5-1.75 inches of lift over the last three of feet of board (one inch or so in the last foot and a half). (measurements are from the center point)
Fish rockers I’ve seen are really all over the place. The rocker will vary with the type and number of fin(s). Remember that because of the short length, you can get away with pretty flat rocker. Lis fish in the 70’s I saw had no more than an inch (most were dead flat) and it was a similar shape (lift) as the hulls.
The Pescado has definate curve in the tail rather than the lift of a hull but it is still pretty flat compared to the kick you see on a typical thruster. The curve works better with the three fin cluster.
Bottom line? Classic hulls and fish have similar rocker shapes.
Flat or lifted tail rocker will give you drive and trim speed, but will take away small turn radius. You can combat that with short over-all length and multiple fins.
Adding a curve to the tail rocker will shorten the turn radius, make the board easier to ride but will slow trim and drive…
Thank you LeeV, that’s just what I was after. The voice of experience.
Interesting side note, just found a mention by Paul Gross that putting vee in back (just ahead of fin) makes the board turn friendly but moves the sweet spot back and makes it more of a tail rider. Kind of a forehead slapper now, but back when I was frustrated having had hull that rode from the widepoint, then got several in a row that were tail riders and I thought it was something I was doing wrong. Always wanted to be more forward on the board.
Looking realistically at what kind of waves I surf most of the time, I think I may have to go with more of a San Diego egg type of board than a full-on hull. Lot more flatness across the width and only shallow roll under the rails. It’s always about the compromises I guess,
All else being equal, the sweet spot is right over the deepest portion of the hull. So you can adust the sweet spot fairly easily as long as you keep the outline parallel.
I always wanted to stick a couple of keels on a Liddle to see how it would go but I never had one of his boards with runners at the same time I had the right keels. I still think that a twin or quad set up on a traditional hull bottom and outline should be checked out. Get some snap without losing the glide.
All else being equal, the sweet spot is right over the deepest portion of the hull. So you can adust the sweet spot fairly easily as long as you keep the outline parallel.
WOW! Last night this set off the light bulb in my head about how to shape one of these.
Just to be clear, I imagine the sweet spot, if you were forced to specify with an “X”, is midway between you feet.
“Just to be clear, I imagine the sweet spot, if you were forced to specify with an “X”, is midway between you feet.”
Pretty much. Just remember that you want the bottom to be pretty flat over the last 6" (back). Running too much V or convex bottom off the tail on these boards pretty much sucks (literally).
PM me your e-mail and I’ll send you a bunch of photos. I don’t have the time or inclination to screw with reducing the quality to something I can post. Sorry.