They’re only like 3 bucks a piece from Carbon Marine. It’s a well made product from a great company.
You can make them for less than .50 cents you also must get at least 24 of the Carbon Marine $69 worth of them at a time to get enough.
Here what I did, and you can step on them, they are waterproof, tuff and they won't come off. You can also make them in different colors: Got two 12”x18”x 5 mm EVA foam sheets one black & one white from Hobby Lobby and the rest of the stuff from just about anywhere and whatever tools you have laying around. These are actually tested, and they pass. You can make them look like anything you want and now my Piranha has teeth.
I cut the triangle pattern template out of cardboard and marked the EVA and cut it out of the white and black EVA with scissors (make sure you cut a reverse pattern if you are going to do it like this). I originally was going to use the round bottom part of the template instead of the oval piece, but it did not work, and I cut it off. Glued (2 pieces) the white to the black patterns together for strength with the E6000. I used masking tape to hold them together but it made a messy glue line that the adhesive from the tape stuck to. If you lay them on a flat surface with some wax paper down first, you can just put something like a piece of board or books on them till they dry, and you won’t have a messy glue line.
For the oval base I used one sheet and the Exacto knife to cut out the rectangle, make sure the cut out is a little thinner than the actual thickness of the two pieces of the spike glued together. Glue the base to the spike with the E6000 and make sure you flatten out glue on the bottom (use a toothpick) and the spike base is flush with bottom of the oval base and will sit upright at a 90° angle to the base. It is foam and you can move it around. Dry them on wax paper or something the glue won’t stick to.
Once dry use the Loctite marine sealant on the bottom of the base by spreading a thin layer over the hole area and stick down to the bow where you want them. You may have to come up with a way o hold the base down flat till it dries so don’t more than you can do that for. I could do about 3 at a time and the glue takes about an hour to set and about 8 hrs to cure. That particular marine sealant is very good for all kinds of boat stuff. Also stick the marked pieces together and the oval base pieces down so you don’t see the cutout marks.
If you save image as on the bow spikes jpeg and print it at 8.5 x 11 it will be the correct size for your template.