To date we have seen many attempts at building artificial reefs using tyres, sand-filled geotextile bags, inflatable rubber bladders, GPS positioned rocks, all of which have failed to deliver “World Class” surf breaks.
So, here on this forum, let’s have an open discussion of what didn’t work, what might work, and why. I’m sure there are Swellnet readers with some expertise in the field, and many more with interesting opinions and insights.
Here is my proposed reef design, go to - www.offshoresurfreefs.com
I welcome any questions or comments on my Offshore Surf Reef concept, and also comments on all previous attempts by others to create surf breaks.
If anyone has any other new reef designs/other information to share please post them here and join the discussion.
The aim of this thread is to build an informed view of the direction artificial surf reef design/funding/implementation should be moving.
looks so easy..frustrating its not being done somewhere.
I'm generally a pretty optimistic fellow, but on the subject of artificial reefs I am decidedly pessimistic. It would be great if this thing works but I'm not holding my breath.
Seems most of the stationary near shore reefs haven't really ever worked. Thoughts on placing more of a bombie style reef setup offshore of straight hand beachies to create refraction and turn surfing wastelands into pumping A frame wedges? Would imagine artificial reefs like a submerged ship dumped in the right place's would have a longer lifespan without being buried in sand, moved around, or sinking. Could double as a fish sanctuary/dive hotspot too if done correctly. Having said that, environmentally, could be pretty suss just dumping more stuff in the ocean.
Bombie style reefs would work if placed the correct distance offshore, but like any artificial reef it needs to be built on rock to be permanent. There's a lot of close inshore rocky reef areas on the east coast, and where there is sand there will always be solid bedrock underneath. In places the depth of sand to bedrock would be too great for it to be plausible though.
They need to stop building reefs on sand. It doesn't matter how good the design is, if it's on sand it'll end up sinking.
Dunno if sinking ships would work. Some commenters here reckon 250 t concrete tetrapods would move so a ship wouldn't stand a chance of staying put. Plus the risk of it breaking up.
But on the other hand parking a ship on the beach at Byron might save a few millionaires beachfront houses so that might work hahahaha. Pasha Bulka round 2...
The idea of a deep offshore reef, to refract incoming swell into inshore peaks is possible, this effect occurs in nature, but the very large size of the structure required and corresponding cost makes it uneconomical. Better to use a smaller structure that waves break directly onto and over- cost efficient/predictable outcome/patentable /commercially viable. Dumped ships? No, dumped anything will not deliver-reefs need accurate bathymetry/accurate crest level in relation to sea level/ and engineered stability so they retain their shape, don't move around or subside. The thing to remember is "prefect bottom shape=perfect wave shape". That is why I'm proposing a prefabricated fully engineered reef structure. It is possible to engineer a stable reef structure on a sand seabed.
Ways to create surf breaks- There has been a lot of discussion of late in the Swellnet articles, comments, and forums regarding different ways great surf breaks may be created. So let’s have a look at a few of these ideas here. I will give you my opinion, and I invite others to make comment.
If we are going to deliberately create surf breaks, then the method/tech used needs to be practical, provide the best outcome for the $ outlay, be adaptable to common situations, and be environmentally and aesthetically acceptable.
Breakwalls and groynes - let’s be realistic, no approval will ever be given for construction of breakwalls or groynes the sole purpose of which is to try to create surf. The same can be said for artificial headlands which are just broader versions of the above.
Gold Coast City Council originally proposed a pair of artificial headlands for erosion control at Palm Beach, Gold Coast, then scrapped the idea following resident backlash in favour of an artificial reef with sand nourishment. This was due to the impact these headland structures would have had on the aesthetic amenity of the beach. Breakwalls have also been suggested as an option for the protection of Belongil Beach, Byron Bay but again no-one wants to see any structures, whether they be breakwalls, groynes, or exposed seawalls built on beaches. This is why artificial reefs, which are invisible, have great potential as a solution for coastal protection.
Submerged “simple” groyne-like structures have also been suggested on Swellnet to trap long-shore sand drift in order to try to create better conditions for wave breaking at that location. In extreme erosion or accretion conditions cross-shore sand movement can alter the seabed level, if we are talking Gold Coast say + or – 2m, and the shoreline location can vary considerably, so any structure like this will need to be much deeper/longer/wider and more heavily engineered than you may think to remain intact and still continue to trap long-shore sand drift- definitely not “simply” a few placed sandbags, rocks, or a row of submerged posts. How effective or reliable this idea may be in improving wave breaking is uncertain, so the cost/benefit may not be there. Anything that relies on a shifting sand seabed to provide correct bathymetry for wave breaking is bound to have its limitations. Best to spend the effort/$ on a reef that sits out further and has the correct accurate bathymetry all of the time. Also, placing any structure just under the water surface along the shoreline will be a safety issue.
Outer artificial reefs to refract swells into inshore peaks- yes, we see this effect occurring naturally, but the broad and shallower outer banks/reefs that interact with incoming swells, i.e. slowing wave speed/reducing wavelength/increasing wave amplitude, inducing wave refraction, are very extensive, so the cost to try to artificially reproduce such a broad scale setup is prohibitive. Again, best to spend much less effort/$ on a much smaller reef structure, or multiple reefs, with the correct accurate bathymetry for waves to break directly over them.
“Re-contouring” existing coral reefs or rock platforms- It is also suggested by some that this could be a way of creating surf breaks. In theory, if the correct accurate bathymetry could be formed waves will break accordingly. However, these areas are protected habitats (or should be in all jurisdictions), and no disturbance of coral reefs, rock platforms, or other natural features should be permitted anywhere. This is why off open sandy bottom beaches are the preferred sites for the Offshore Surf Reefs concept.
Geotextile sandbags, rocks, or any other collections of individual units- these things have all been tried by others to create surfing reefs, with varying degrees of success or failure. The latest by Gold Coast City Council at Palm Beach was attempted using GPS placed rocks. All of these suffer from the same problem- the correct design bathymetry and reef crest levels cannot be built accurately enough. The exact design bathymetry and reef crest level in relation to Mean Sea Level (MSL) needs to be attained to create perfect waves. This is why a fully engineered, prefabricated reef form is used for the Offshore Surf Reefs concept.
My colleague, Wayne Bartholomew (ex CEO and President of the ASP), and I both share the vision of creating “World Class” artificial surf reefs, and in conjunction with the Griffith Centre for Coastal Management, Griffith University, Gold Coast, have for some time been advocates of a constructing a trial reef in the Gold Coast/Tweed area. We are currently seeking private investor/s for the trial project.