Artificial Floating Coral Reefs


Oh? That’s encouraging. Do you have any footage of the tests?

Also, were they made from netting like the ones pictured above, or solid?


The scale is whatever the builder wallet can handle :smile:

The grey “thing” inside the breakwater is a coral reef.

If you think that the structure is inefficient, feel free to jump on Sketch Up, build a more efficient structure and post it so I can comment on it :wink:

Breakwaters are a myth. I don’t know who came up with this “breakwater” idea of being a necessary “thing” for seasteading. As shown in my designs as part of the structure, the only purpose of that “breakwater” is to somehow “protect” that reef. Which, out at sea in a big storm, will still be subject to strong currents and a significant wash out.

I don’t see how “a larger area” can be “protected” from,…what? The constant motion of the ocean? Is never gonna happen,…no floating seastead will ever be terra firma.

(Chad Elwartowski) #43

I had footage but lost it years ago.

I was using ferrocement spheres. I had 7 spheres (about 1.5 foot diameter each) tied together in a disk shape.

I put them in one of those blow up pools and made large waves from one side, on the side past the spheres the water was level.

When the waves hit the spheres they bounce around like ping pong balls and lose their momentum and just die out.

I was thinking 10 meter spheres, 2 deep all around the seastead would do the trick against 98% of the waves. And if the people were really worried about one of those huge waves they could pay to go 3 deep.

(Wilfried Ellmer) #44

Shell building will be enough to protect the real estate against draupner waves (allow a massive overwash of structures 4 times a year).


The concrete ball idea Elwar mentions sounds like a good outer defense. My personal idea in regards to both the artificial reef and the mangroves was to produce ‘bowls’ out of small gauge screen with a bar or tubing superstructure floated by buoyancy tanks or pontoons around the outside ballasted just enough to remain below the ocean’s surface. The ballast would require pumping over time to avoid sinkage as the accreted material grows, however once thickened to two or more inches of aragonite, returned to positive buoyancy and pumped out, it could be used for saltwater tolerant agriculture, mangrove starters, algae ponds, etc. The underside of the structure could act as a limited artificial reef as well as protecting the undercarriage of the structure from significant corrosion (albeit at the expense of efficient relocation of the structure.)

As part of a cheap and easily expanded seastead it could allow rapid surface expansion provided sufficient electrical power, steel, and wavebreaks were available.


Sounds great :slight_smile: Just out of curiosity though, how did you plan on mooring them? I’d imagine all those lines in close proximity of each other would create a fouling hazard.

(Chad Elwartowski) #47

I have a fairly elaborate idea for doing the mooring that would get the least amount of lines attached to the surface. It will be easier to show it when I do the design for the contest.
Similar to a goal post where the “center post” can be tied onto by many lines.


Sounds interesting, I’ll be interested to see the design. Do you have some kind of rigid element preventing them from ending up in a clump downcurrent?


My original idea was for shallow water, where they could be anchored to the bottom. If you anchored them in a grid, they would all move the same amount with current, and not run into each other, plus not drift off. If we did the reef columns or any other floating aquaculture in deep water, running rigid elements between them would easily solve the problem. For the reef, I would have made it so that the rigid material is reef as well, just because reef. For aquaculture, it could be different, since they wouldn’t be for growing stuff, but the basic rigid element would be the same.

(Chad Elwartowski) #50

If they are tied together well they should not clump.

Similar to this on a larger scale.


I think I’ll just wait for you to post your diagram :stuck_out_tongue: I’m sure it describes it perfectly.

(Matias Volco) #52

I thought I had posted this before:

Maybe forget about the vertical water pump, and just consider that such a breakwater imitates the conditions found in the large barrier reefs: I imagine the water collected in the floating pools would heat up at least slightly and it would also be interchanged/moved around regularly depending on the ocean conditions, creating some of the parameters corals need to grow.
So here you can have a breakwater marina with a silly villa on top of it and underwater garden. Instead of property tax the owner could perceive profit from providing the service of calm waters.

(Matias Volco) #53

Rishie Sowa’s much discussed spiral island proved that in protected water you can create the substrate (medium) for mangrove growth with plastic bottles attached in nets. It sounds like a small scale approach, but cities waste literally millions of plastic bottles, and unfortunately overpopulation means there’s enough people willing to separate them and sell them just as they do today with plastic and cardboard. considering reusing the plastic bottles consumes less energy than recycling them this would be an absolute benefit provided by the seastead to the land cities.


The problem with it however, as indicated by the second island, is that such a design lacks the structural integrity necessary to survive along the coast nevermind in deep waters. Research on building an entirely recycled or biologically grown floating island is what eventually lead me to concrete some buoyant stone design is likely best. At this point foamed concrete with a waterproof cement/dense concrete outer shell, if possible, with a steel mesh mesh skin attached to the belowwater exterior skin in order to accrete a hardened outer layer of biorock (intended to further waterproof and ideally repair cracks in the outer skin that might otherwise allow the foamed concrete to become water saturated and lose its buoyancy.) That said, integrating oceanic waste into future expansion as filler is certainly a valid possibility.But not one I would rely on as a primary structural member.

(Wilfried Ellmer) #55
  • the poor man’s floating island was looking in the same direction…the final answer is probably not either or, but rather “all of those methods” where they are convenient…


My idea would pretty much be that design but in a large ring. Also, the interior of the reef area would be a wall like the exterior, and the exterior wall would be bigger (but also much farther out). There would also be much more inside the interior part of the ring, because it’s a city, not a big empty disc.


That looks really nice! But, the problem with a floating breakwater is that it will float just like any other ship :slight_smile:

(Matias Volco) #58

Why don’t you like breakwaters?
When I kayak on the leeward side of an anchored cruise ship I can comb my hair, when I go the windward side my hat flies off. Are you suggesting big stuff floating in the water have no break-waving capabilities whatsoever?

Yup, a lot bigger and fuller. Here many shallow hexagon lagoons create the breakwater for a bigger deepwater lagoon, like an atoll.
There are shallow underwater houses on them (the round domes), and Delta’s city inside. :blush:

(.) #59

Waves are more difficult to stop than wind. I would think.
Though ships probably have some breakwater capacity too.


The way I see the breakwater working is just by the sheer mass of both the breakwater and the city. The breakwater would probably have to have some rigid connection to the city, so the whole thing would pretty much be a big disc. A really big disc. It’s pretty hard to flip a big disc. Remember, the outer breakwater is supposed to break the waves, not stop them completely. It would be designed so that waves would go over the top of it but be broken on the other side. Plus, we’d have a lot of natural reef and mangroves (inside the reef they would probably survive) to help break up the water that comes over the top. The final ring of wall around the city would just keep the water out.