A failed attempt to prove Mark Twain wrong


Mark Twain is famous for his quote "Buy land they aren't making any more of it".

This is an under-edited post exploring the costs of making more floating land out of fibreglass boxes that you can then have sitting in the ocean.
Living in Britain the cost of land is very high, at least compared to any kind of global average. I've been wondering if a super low-cost construction on the water could ever be cheaper.

Starting with some reference numbers:




2080 for 16*120m rolls 0.95m width 225gsm

1.14 GBP/ m^2


Google claims this source says 2 layers for 300gsm


Beams at 2GBP/meter

8 sheets

4 beams 2440

4 screws per panel

Cost of mold

8*8.36 + 4*2.440*2 = 86.4

Cost of fibreglass:

Surface area is 8*1220*2440 = 23.81 m^2

4 wraps:

4*23.81 * 1.14 = 108.57

Resin is probably twice the cost of the fibreglass


Total cost for a box

3*108.57 + 86.4 = 412.11

Total per sqrm

So even if this works it’s way more expensive than simply buying land.

At 70 per sqm, we are an order of magnitude away from our goal.

In bulk, British farmland costs 6k per acre

We are currently at 280k per acre

Halving the cost still doesn’t even get us close.

There are advantages to our approach in that we aren’t limited to farm use etc. There are also drawbacks, we don’t have a ground to dig into, except the ocean floor obviously.


Using the non-aggregate land cost we get 

This is a much more manageable target we only need to get about 6 times cheaper.

If the resin doesn’t cost 3 times the fibreglass and we don’t do 4 layers well a low ball estimate for this could be

3 wraps and resin cost in line with fibreglass cost, with a mould that is reusable

3*23.81 * 1.14  * 2 = 163

Still way too high but we are closing in on the 42k/acre

86.4 + 23.81 * 1.14  * 2 = 140

We are going quite large on the surface area so I wonder if we drop that down how much we could save

 4*2.440*2+ 5*8.36 =61.32

2440*300*4+2*(2440*2440)= 14.84m^2

14.84*1.14*2 + 61.32 = 95GBP/4 by 4

That actually gets us really close to the cost of land on a small scale even if we end up with quite flimsy (because of the single sheet) and not as buoyant construction.

4*2.440*2+ 4.5*8.36 = 57.14

2440*300*4+2*(2440*2440)= 14.84m^2

14.84*1.14*2 + 61.32 = 95GBP/4 by 4

Making it even more flimsy to really push the boat out, pardon the pun, and have the mould taken out we can get down to

14.84*1.14*2 = 33.84

We are still above the cost of land in bulk but at least we have got to a point which is cheaper.


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