Surfboard Fin Boxes — What’s Best

August 26, 2017

I’m going to describe what in my opinion, are the most desirable qualities in a fin box. This is not a discussion of what’s out there, but a discussion of what’s best.

First, why a fin box instead of glassed on fins? So you can easily tune the board for best performance, and easily replace damaged fins. I discuss this in more detail in my book on surfboard design.

Box to board connection should be as strong or stronger than, a glassed on fin.

Fin does not “wiggle” in the box (solid as a glassed on fin).

Box is strong enough that the fin can be broken with no damage to the board or fin box.

Fin cannot loosen or get knocked out while surfing.

High strength to weight ratio. Yes, it has to be strong, but it also has to be light.

There are no screws or other fasteners to retain the fin and no moveable parts. No threads to strip, no fasteners to lose, and no special tools needed.

The design of the box alone securely retains the fin, and yet the fin easily “pops” into the box and is easily removed with no special tools needed.

This box was designed so custom fins can be easily made to fit securely, using simple hand tools. If you want to experiment with custom fins (made by yourself or anyone else) this is the box you want.

One other feature is that a leash connection point is provided, so you won’t need a leash plug, and you’ll never have a leash plug failure.

Does this fin box exist? Yes — this has been my personal fin box since 1981. Do I make them for anyone else? No, not so far, but I’m interested in finding some entrepreneur or manufacturer who would like to get these boxes into production.

Contact me via a comment on this blog or by email:


Edge Boards and the Mysterious Mr X

March 27, 2017

The Surfer’s Journal published a good article on Edge Boards in the Feb/Mar 2017 issue (volume 26, issue 1). This gives the history of low-drag (high-speed) surfboards. Even though I originated the “edge board” design, I did not know how much influence it had on short board design. and only from the article, did I finally find this out. The time period was late 1967 (when I first started making surfboards on the North Shore of Oahu) to late 1969. Earlier, I had made a couple of surfboards in Southern California.

Switch surfboard fin boxes?

March 16, 2013

Someone searched my blog with the question: “Is it possible to switch surfboard fin boxes?” The answer is YES; in fact anything is possible. Anyone competent at surfboard repair can do it. If you want to do it yourself, it’s not too difficult.

Basically a fin box is installed by cutting a slot or hole in the bottom of the board and the box is resined in. There are some variations on this so be sure to get the box manufacturer’s recommended procedure for installation and follow that. Removal of the old boxes can be done a couple of ways: One is to cut around the old boxes and pull them out, and then repair those holes by resining foam plugs in and glassing a patch over the plugs (be sure to sand a taper on the surrounding glass — you want the repair to be as strong as the original glass job. You now install the new boxes per the instructions for a new board installation. The other way is to not remove the old boxes but to set-up a guide for a router as if installing the new boxes in a new board. In this case you are going to route out the old boxes (or part of them) just enough to install the new boxes and resin them in (epoxy is likely your best resin choice). In this case you do not need to make any repairs (unless the board had already been damaged).

If you decide to route out the old boxes, be sure to remove any metal (screws, plates, etc) before starting. Also note that the router will “bite hard” on the dense box so be sure that your guide is well attached to the surfboard and take a series of light cuts until you get to the depth desired. In most cases do not remove any parts of the old boxes that were outside the router slot, you’ll retain better strength for the new installation.

Finally, if a surfer is changing fin boxes, it’s probably a performance issue. In this case, were the original boxes in the correct location? I suggest you get my book “The Basics of Surfboard Design” and find out.


Make more waves!

April 2, 2011

I recently received word of an Australian surf spot that was greatly improved by simply moving some boulders around. It was done at minimal cost and with no net impact on the environment. Take a look at this address: (please use caution with this site, when I last checked it my computer blocked it saying it contained malware)

This website has some good discussion of various surf making projects and should be of interest to all surfers.

In April 2009 I did a series of blog posts on making waves, if you haven’t read them, I’d suggest taking a look (click April 2009) in my blog archives. The above mentioned project is an example of what I’ve been advocating.

I’m sure that every surfer knows of places that currently have funky waves, but could have good waves by shifting a few rocks, etc. around on the bottom. We need to educate ourselves about the possibilities, and then talk to our friends and get a great enough number of people interested in having more and better surfing waves. With interest from enough surfers we’ll be able to make more surf spots.


En Espanol? Si! Si!

April 2, 2011

I’d like to announce that a Spanish translation of my book “The Basics of Surfboard Design” is off the press and has “hit the streets” in Barcelona, Spain. For those of you that speak Spanish, or have friends that do, you can learn more about this by visiting:

 I’ll be working with the Spanish publisher to find a way to distribute the books in the USA.


Surviving wipeouts/whiplash

February 10, 2011

Wipeouts are a significant part of the surfing game and add to the spice, even though we normally “kick” ourselves for making the mistake that caused the wipeout. I always figured if I wasn’t getting hammered by the wave once in a while, I wasn’t surfing on the “edge”. I normally tried to set myself up so I had about a 50/50 chance of making the wave – even a slight mistake on a successful takeoff would usually mean I was going to get passed up by the wave. While I was always looking for fast hard-breaking waves, Pipeline (rights and lefts) was my #1 choice.

From the above, you can see that my “wipeout dues” were always well paid! But after a while I noticed something interesting – the most common wipeout I experienced was one in which I fell out of the “lip” and landed upside-down on my back. Then I noticed that my neck would hurt from the impact. Well of course, wipeouts aren’t supposed to feel good, but on the other hand, surviving them does feel good — you know you overcame a difficult situation. This went on for a number of years and I started wondering why my neck would hurt – it wasn’t really hitting anything except water. Then I realized what was causing my neck to hurt; when I landed on my back, I had an automatic reflex to keep my head up so it wouldn’t impact what I was landing on. I imagine most of you, if you fall on your back on a hard surface, reflexively hold your head forward to avoid bashing your head in the fall. Holding my head forward to avoid impact caused the neck vertebrae to take the impact (similar to whiplash, but a bit different).

Once I realized what was actually happening I was able to figure out what I could do to try to prevent this “whiplash”. I decided that instead of holding my head forward, I should push it back at the time of impact and push my head into the water. But it wasn’t quite that easy; I had to overcome the reflex, and I had to do it at the instant of impact. It took some concentration (no I didn’t practice wipeouts to learn this) I was going against a natural self-preservation reflex to do this. When I finally gained enough control over the reflex (the first few times, I forgot to do it) I pushed my head back as planned. I felt like I was going to bash my head – my thoughts were “Is my surfboard under my head? Am I going to shove my head into the reef?” These thoughts were very strong, a bit like taking a flying leap off a cliff. Well it worked! It was better than I expected; instead of a sore neck, my neck felt great, and I had correctly understood the problem and how to resolve it.

I offer the above for your consideration, if you make a habit of doing this, there could be times it could get you in trouble (for instance if you were to fall back from your skateboard, you would bash your head.) There have been a couple of times I hit nearly dry sand in the shorebreak with my butt (the water sucked out more than I had expected). If I had shoved my head back at those times, it would have been a mistake.


Drugs and Surfing

November 14, 2010

Due to recent events in the surfing world, I realized I should write this post. We live in a world that has become increasingly dependent on drug use. This is true whether we think of street drugs or medical drugs. Is there anything that we should know about drugs to help us make intelligent decisions? I think there is and perhaps my own experiences and studies will be of help.

The first thing I’d like to say about drugs is that all are poisons. You can test this out for yourself by taking an overdose (OD) of any drug there is and observing the result. Clear enough?

While a few medical drugs are useful (probably less than 5%) most of them cause more harm than good. This is a nutritional/health issue and is not the subject of this post, but some medical drugs are used for non-medical purposes. This is commonly referred to as “recreational” drug use, but I object to that term because it’s a marketing term coined and promoted by those that wish to poison you and make a profit by so doing (drug pushers, ya know).

If drugs are poisons, why do so many of us use them? I believe this can best be stated by the words “to feel better”. Note that I am including any “benefit” that drug use seems to provide. If drug use makes us feel better, what’s wrong with their use? This point is the real key to drug use; keeping in mind that the drug is a poison, it works by either blocking some pain (physical or emotional) or by speeding up/slowing down some body physical/chemical process. The “high” (feel good, etc) is the initial, desired effect, but the “crash” (come down) or hang-over is the actual over-all effect of poisoning the body. You cannot repeatedly poison the body without making it worse. How fast the body gets destroyed is only a matter of how potent the drug and how frequent the use.

At this point, I’m going to make a statement that may shock you and I’m sure that some will violently disagree. After extensive study and my own observations, I realized that drugs do not make a person high. Now some of you will say: “Bob, you’re a fool, I get high all the time from drugs.” Yeah, so did I; except that was not actually true. That “high” (feel good, etc.) is actually a small taste of how you should feel (be able to perform, etc.) all the time. You actually get a small taste of how things should be, but at the price of gradually getting further away from that desired state due to the cumulative effect of poisoning the body. Those of you that think you get a spiritual boost by drug use, this also applies to you. You cannot use a physical substance to make a spiritual gain. Yes you can perhaps “get a glimpse” but the poisoning will prevent all spiritual gain in the end. No matter how you look at it, or what your reason for drug use, it results in a nasty trick that gives you exactly what you were trying to get away from in the first place.

For more information about drug education, prevention, rehab, etc. visit:   also check out:

You can also contact me at: and I can show you how to get far beyond anything you might have been looking for via drug use.


Venturis and dimples

October 9, 2010

I was thinking of calling this post “Carburetors and golf balls” but I figured that would attract gear-head golfers. Over the years I’ve noticed that surfers often talk about how fast they go (or want to go) on their surfboards. At the same time I have observed that they choose slower board designs in preference to faster designs. Why is this?

Let me re-state here that the best surfboard design is the one that a surfer likes the best; there is no other standard of “best”. Surfboard manufacturers will tell you theirs is the best (they want you to buy it) but only if you try it and like it, does it become “best” for you. Surfers usually prefer control above speed so fast is normally only a marketing term.

I previously posted about dimpled surfboards and a lot of surfers have been searching for that post, so I thought I’d add a bit. With golf balls and surfboards we have a fluid dynamics problem which will require some study if you wish to learn more. A golf ball is not a good shape for moving through the air rapidly. The best shape for greatest distance (speed) would be a streamline (“teardrop”) shape that was very smooth (no dimples). We can see that this would not make a good golf ball since it wouldn’t roll. I suspect that dimples are not the best surface treatment for a golf ball, but it may be that roughed-up surface (scratches) would be. But try selling an ugly scratched ball against a cute dimpled one.

So why does the dimpled ball have less drag than the smooth one (at certain speeds)? The smooth ball is a poor shape and air flowing around it forms eddies behind the ball increasing drag. The dimpled ball enturbulates the air next to the ball which reduces the eddies, resulting in less overall drag. A surfboard has a different fluid dynamic problem and dimples are not the way to increase speed but they might be useful for other reasons (which I don’t have time to discuss here). In any event, if you want to try dimples, I suggest a piece of course sandpaper; scuff the surface (of the finished board) where you want the dimples and you should get the same effect.

Now a word about venturis: a venturi is actually a tube with a narrowed section near its center. It is designed to create a pressure drop in the narrow section for various purposes. The most well known use is in a carburetor where the venturi is used to “suck” fuel into the air flowing through the carb. Note that the air-flow speeds up through the narrow section but this speed-up comes at the expense of increased overall drag. The auto racers know this and (rules permitting) will choose fuel injection (no venturi) over carburetion every time, because a fuel injected engine will flow air in faster (more power) than a carbureted engine (the venturi slows the flow).

What does this mean for surfers? I’ve never seen evidence of an actual venturi on the bottom of a surfboard. A venturi will add drag (slow the board); yes the flow does speed-up at the narrow section but you have to look at the whole picture. You only get a localized speed-up by forcing the fluid through the restriction and that force takes energy (equals more drag). This does not mean that “venturi-bottom” surfboards are not good or even that they are slow. It just means that “venturi-bottoms” can only be seen as a marketing term and are based on a misunderstanding of what a venturi is and how it works.

There is one fin for surfboards that does appear to have a venturi. That is the Turbo Tunnel (TM) fin. While we can see from the above discussion (or by testing it in a water flow) that it will have more drag than the same fin without the tunnel pod, that does not mean it’s not a good fin. It appears that a lot of surfers like it so that means it is a good fin.

Slowing a surfboard a bit will often enhance performance and control and that is usually more important than speed. Check my earlier posts on this (“Fast or slow” and “Slow or fast” both posted March 24 2009) for more. My advice is to look for a surfboard with the best control; then start looking at ways to get more speed without sacrificing control.


En Espanol?

October 2, 2010

Attention Spanish speaking surfers: I recently signed a publishing contract with a publisher in Barcelona Spain. This publisher will be translating “The Basics of Surfboard Design” into Spanish. A whole new area of the surfing world will soon have access to surfboard design theory. Additionally, the publisher requested an option to publish in French and Portuguese so if the Spanish version sells well, French and Portuguese speaking surfers will get their chance too.


Shaping by the numbers

July 4, 2010

Based on some of the search items that landed people on my blog, some of you should be contacting me or posting a comment; I could be of help with some of those questions. (I didn’t answer all possible questions on this blog yet – I don’t even know what they are.) Note that the following discussion is not just for those that want to shape a surfboard; it’s for anyone that wants to get a better board than what he or she has. Use it to: find a better used board, find a better new board “off the rack”, help to order a custom board, or as a guide if you want to shape it yourself.

One thing that I’ve been noticing is that many of you want numbers. This could include measurements to describe the: rocker, fin placement, fin size, board thickness, etc. It is true that any surfboard could be described by a series of numbers (and of course that is how a computer runs a shaping machine.) However it is not possible for anyone to tell you any meaningful numbers, unless he is working directly with you and works out exactly what you want your surfboard to do.

Here is my advice for a starting point for numbers (you actually don’t need numbers, you need relationships). But you do need a starting point and it can be described with numbers. If you’re a newbie, get some help but your main problem will be catching waves and standing up. You want a board that is easy to paddle and to catch waves with (longer, wider and thicker helps) once you build your paddling strength and are getting rides easily, it’s time to decide if you want a different board. At this point you have the starting numbers; they are the measurements that make up the shape of the board you are riding. Those of you that have been around (including the experts) your starting point is the board you’re riding (or in some cases recent boards).

The first thing you have to decide is how you want the surfboard to ride; you will be looking for an improvement over what you have. This is a key point and the better you pin this down, the better your chances are for an improved board. Once you establish what the improved ride should be like, you simply figure out what changes should be made to your existing board, add to or subtract from, its measurements, and you have the numbers for your new surfboard. Simple, huh?

Yes, I’m chuckling because I understand what you’re likely thinking. “Great, Bob but what dimensions do I change, by how much, and in what direction?!!” Heh, heh, that’s the “Great Sacred Mystery” of shaping that only the top gurus know, and you have to…. I’m kidding you of course, because there is no mystery, never was really, it’s just a matter of how closely you look at all the elements of the surfboard and of the waves, and come to an understanding of them. I wrote “The Basics of Surfboard Design” so we would have all the important elements in the most straight-forward, understandable, format possible.

Ok, so I got you to where you know the starting point for your next surfboard, now you have to figure out what the new measurements should be. Read my book and examine each line on your surfboard in light of what I say that line controls. Think of how your board rides in terms of each line, for instance rocker: how does your board trim compared to where you are standing on it and under what conditions (faster/slower, larger/smaller wave, more/less powerful wave, etc.) You need to be able to understand each line separately, and then you need to be able to see how those lines interrelate.

From some feedback I’ve gotten, there are some who seem to think that my book is for beginners, but it’s actually for the most advanced shapers. It was written to be understandable by anyone if they have an interest, but the most advanced shapers are only manipulating the lines I discuss and they get the results I describe. I’ve listened and talked to, email chatted with and read articles by some of the top shapers and I suspect that some of them could use a better understanding of surfboard design basics; still, they are all great craftsmen.