Have You Heard of a Manta Board?

I find few things in life more gratifying than discovery: learning, exploring, and even creating exciting new vistas.  It's no lofty concept: the new is always presenting itself to us.  Take, for example, a recent favor I did for my friend, an aquatic biologist: helping him create a manta board.

What's a manta board?  It's for scuba diving, of course!  But when my friend first asked me to help him make a manta board, for an upcoming trip to Haiti's coral reef, I thought he wanted it to scare predators (or attract them...).


Turns out a manta board isn't used to fool any fishes, but to allow a S.C.U.B.A. diver to stay dozens of feet below the surface, while being towed by a boat.  The diver grasps the simple manta board, and tilts it up or down, either bringing himself to the surface, or driving himself down to the sea floor, against the pull of the boat. 


My friend planned to use his manta board to survey the biodiversity and density of coral and fish species along a certain area of Haiti's coastal coral reef.  Colleagues on the boat will tow him at a few knots, while he records what he finds on sheets of underwater paper and pencil.


Making a manta board isn't hard, and this job wasn't one of my most challenging commissions.  I cut the blank from 1/2" marine plywood using the Festool TS-75 plunge cut saw and guide rail.  Then, using my friend's outstretched arms & hands as a template, I marked the locations of the leading-edge handholds.  Next, I found the center of the trailing edge of the board, and marked out a handle for one-handed operation.  The handle and handholds were started with a 1/2" drill, then finished with a Festool Trion jigsaw.  The rope tie holes were made with a Forstner bit and drill guide.  Then I broke the edges and sanded the surface to 180 grit with a Festool 6" orbital sander.  Finally, the whole piece was finished with one coat of marine spar varnish, which took 5 days to dry.

Still, it was a very interesting 30-minute project.  He and I discussed pros and cons of different handle designs, tow-rope tie locations, etc.  We also came up with a few innovations to the traditional manta board, such as holding down the water-proof paper with spring clips instead of bungee cords.  Fascinating and fun! :) 


Now I know what a manta board is, and so do you.  Who knows, maybe one day you'll go diving and know to ask for a manta board, so you can swoop along the sea floor.  Sounds fun.  Just try and go diving before all the coral are gone.


-isaac