View Full Version : Makeshift Monofin (tutorial)

05-20-2013, 05:57 PM
Hey! So as some of you may recall, I was in Ireland/Europe for the last four and a half months. It was an awesome trip, and I decided later that I really wanted to do some mermaiding.

I had the skin of my tail, but I didn't have my monofin since it was too big to bring with me on the plane and didn't fit in my luggage. Originally I was going to just buy a new one while I was in europe (since without my extension modification it would have been small enough to fly home with), but it turned out to be much to pricy to do this with shipping costs :( They more than doubled the original price! Ouch.

Anyway, here is what I did anyway to make a temporary monofin to use for photoshoots!

(NOTE: I would not recommend using one of these permanently, and cannot vouch for how they swim, but I fully expect they are not as good as a normal monofin. This is something I did as a temporary solution for photoshoots rather than something I planned to rely on as a propulsion device. That being said, I think it could work underwater, but please be careful and use good judgement before jumping into a large body of water with only one of these! Do not rely on it as a swimming aid, but think of it more as a modeling prop :) )


- Craft foam sheets (thin, mine were maybe one or two millimeters thick). I found them at a craft & hobby store.

- Duct tape--I used white colored Power Tape, since it's VERY waterproof, and the white color made it so that it wouldn't show through the material on my fluke. I got this from a nearby hardware store.

- Metal washers, flat (kind of optional)--I used 4 M16s. Basically, something to help weigh down the fin a little since the craft foam makes it boyant. Four was fine for me since I was mostly posing above water/only partially submerged, if you wanted this to do more underwater shots I would recommend more or heavier. If you're not using it in water at all or don't mind that your fin floats a lot, you can leave these out of the design. I got these at the hardware store as well.

- Cheap flip flops! I just used the generic rubbery foam kind. You want the straps to be as snug around the top of your feet as possible (though not painfully so). This might mean going a size or half size down form what you might normally wear. I got mine at a nearby cheap department store.


- Elastic band material, like the kind you might find in the waistbands of shorts. You want it to be pretty thick, and stretchy but not TOO stretchy--keep in mind a lot of these will loose some of their elasticity in water. If you can find any that say they're resistant to water, that's probably a plus, but I didn't happen to. I found some at a sewing/fabric store in a mall.

- Scissors
- Pen/marker to draw on the above
- Your tail/fluke to trace


Okay, so I remembered to take pictures for some of when I was making it, but I made this from around 1am-4am, so by the end I was too tired to keep up with that >.< Sorry! I will try to explain in words the best I can.

Okay, so I started by laying out five sheets craft foam sheets on top of my fluke, making sure that it was always at least as wide as the material. Because of how it's layered, this means that there is less foam at the end of the fluke, and it's thicker/more layers in the middle. This is actually useful as it makes a nice flowy effect that increases at the edges.


Make sure the foam goes UP into the tail underneath where your feet will be! It's a good idea to have the foam go two or three inches higher than where your heels will actually be placed--you can always trim it later.

Then, I attempted to glue the sheets together with the super duper waterproof glue the man at the store sold me when he told me they didn't carry E6000 (my original plan for holding everything together). It did not work on the foam at ALL. Instead, I ended up rolling duct tape into a circle to make both sides sticky and using it to tape the sheets of foam together. I used... probably more than I needed to. Several lengths of duct tape between each sheet at least. You can't see the tap, but once I did that, I put my fluke on top of the glued sheet to trace the outline onto it.


Now, I only traced the side edges of the fluke, not the end, because I needed to make sure that fit the end curve of my fluke where the velcro is inside.


You can see how the foam overlaps better in this picture. I cut out along the above lines, and then put the foam outline INTO my tail.


This gave me a better way to draw/trace the end :) Mine wasn't perfect, but it didn't really need to be for this project.


What I did next was put another layer of craft foam onto the edges on the opposite side. I would not say this part is necessary. I thought the foam by itself was too flimsy, but once I added the final layer of duct tape it had stiffened up quite a lot and ended up removing some of the red and orange foam you see in this next picture. It really depends on how stiff vs flowy you want the fin to be I think. I also added a plastic sheet to mine under the yellow foam, that I got from taking apart a flimsy plastic binder, but in the end I don't think it actually did anything for the fin and just made later steps more difficult. HOWEVER, if you want to use this to actually swim in, it's a good idea to put a stiffer layer in now, towards the top/middle, so you get some propulsion, like plastic sheeting or lexican or something. Otherwise, it won't give you much push. If you do, make sure this layer goes all the way to the top where your feet will be attached!


As you can see, I also began attaching the flip flops. You can kind fo see where I duct taped them to the fin here.

To position them, I recommend you put the foam part inside the tail, so it's possitioned correctly. Then, put some rolled duct tap on the bottom of your flip flops. While wearing them, carefully put your tail on--it may help if you put something heavy, like a large book or table leg, on the bottom of the fluke/foam to keep it from moving around when you do this. Try to keep your feet a bit above the foam as you're putting it on, but priority is on not stretching/stressing your tail too much here. When it's on properly, press your feet/the flip flops firmly onto the foam so they stick in place. They should now be in the correct position for wearing the monofin inside the tail.

Remove your feet from the shoes and take off the tail, then remove the monofin. Now you can trim some of the excess foam off the back edge of the craft sheets to get the result shown in the above picture!

This, sadly, is where I stopped taking pictures :/ Really wish I had some now, but we'll just have to suffer without.

Next, put your feet into the flip flops and mark a dot about 1/2 inch from each edge of the shoe, towards the back of your foot but in front of your heel, behind where the toe-straps attach. You are going to punch through the shoes/foam here to make a second strap to go across the top of your foot here, so they are more likely to stay on. After you punch your holes (I used scissors and a kitchen... stabby thing... shaped kind of like a screwdriver, I actually have NO idea what it was really for), take the elastic and cut off about 8 or 9 inches. feed one end through one of the holes, and tie a large knot on the end (on the bottom side of the monofin) to keep it from pulling through. Feed the other end down through the hole, and then put your foot into the flip flop. Pull the elastic so it is TIGHT (remember, elastic often loosens in water, but don't kill your circulation!) on your foot, and then make a mark on the elastic where it meets the level of the flip flop. This way, once you remove your foot and turn the fin over to tie your second knot, you will know how far the elastic needs to be pulled through the hole. If there's a lot of extra elastic band on the end, you can trim it, but make sure to leave at least an inch or two so the knot doesn't come undone.

Repeat this process for the other flip flop! Since I was not planning to really swim in my fin, I stopped here. If you are planning on more underwater usage, you will probably want to add another elastic strap to go behind your heel. You could do this by punching more holes in front of the ones you just made (for the strap that goes on top of your foot), or tying/sewing some extra elastic band to the strap you just made.

The fin is nearly done at this point! It will now hopefully stay on your feet reasonably well. However, it's a good idea to give it some more strength. What I did next was cover the entire thing in a layer of power tape. I ran some strips longways down the edges, and then just striped it across the rest. As you go, push firmly on the foam to make sure you're not creating air bubbles, but don't worry to much about that. For the sections with the flip flops, I lifted up the front of shoe and duct taped below it, then just actually went over the soles of the flip flops with duct tape and ran it along the fin so they were SUPER attached and would absolutely not fall off during my shoot.

Actually, you could probably cover the foam with duct tape BEFORE you attach the flip flops. That might make more sense or be easier in the long run :confused: I just didn't think of it at the time! I leave that to some of you to experiment with :)

Now your monofin should be covered in tape, and the shoes should be pretty well attached! However, it's inevitable that you got some air trapped inbetween the foam layers. This will make the fin extra super floaty, but don't worry about it, because you're going to cut slits into the tape/the first layer of foam. Take scissors or an exacto knife if you have one handy and make a few shallow cuts into the fin, parallel with the direction of the flip flops. There don't need to be many, I did around 5--two towards the bottom sides of the fin (spaced out generously), one higher up in the middle, two even higher and a bit closer than the ones at the bottom because the fin was narrower.

Now, when you take your fin to wherever, you can submerge it in water and push the airbubbles out through these slits. The water that gets in as a result will help counteract the buoyancy of the foam as well.

As a last step, you can put some of the heavy metal washers onto the bottom edge of your fin. Not right at the bottom, but towards it. This will stop the end from floating up and away from your feet if you're underwater, or make it sink slightly if you're just submerging the tip of your fluke.


I ended up with a totally workable monofin, that was bendable enough for me to fold and stick into my backpack to take on the flight over, but stiff enough to hold it's shape for pictures!

You can see here that it wasn't too stiff and molded itself a little to the surface I had it on, be it flat or curved...



...but it was stiff enough to hold it's own shape if I turned it upright :)


Anyway, I hope this might be of use to other mers sometime! It's a good cheap alternative to expensive monofins when you're in a pinch, although clearly not as functional. Again, it's not meant to be a replacement, but it was very useful for me to be able to recreate the look of a real fin quickly and inexpensively, and I thought it might be for others as well--especially for dry events.

If any one has any questions about the materials, how I made this, or anything else, please feel free to ask here or PM me!

(If you are interested in how i made my tail/extended my normal monofin, I have it documented pretty well on my tailmaking thread (http://mernetwork.com/index/showthread.php?2548-First-time-tailmaking-Jade-s-attempt), and am always happy to answer questions there about those things)


Mermaid Dottie
05-20-2013, 06:19 PM
Great for photoshoots when you're not actually swimming. I like the ingenuity!