# Diego Garcia base: what are these rectangular holes in the coral for? **URL:** \ **Category:** Factual Questions\ **Created:** [December 24, 2013, 12:30pm UTC](https://boards.straightdope.com/t/diego-garcia-base-what-are-these-rectangular-holes-in-the-coral-for/677075 "2013-12-24T12:30:50Z")\ **Posts on this page:** 17\ **Page:** 1
**Author:** ![Colophon](https://avatars.discourse-cdn.com/v4/letter/c/f05b48/32.png) [@Colophon](https://boards.straightdope.com/u/Colophon)\ **Post date:** [December 24, 2013, 12:30pm UTC](https://boards.straightdope.com/t/diego-garcia-base-what-are-these-rectangular-holes-in-the-coral-for/677075/1 "2013-12-24T12:30:50Z")
I was looking at aerial images of the US base on Diego Garcia in the Indian Ocean on Google Maps and noticed lots of quite regular rectangular holes seemingly cut/blasted out of the coral just off shore. [utl=http://goo.gl/maps/LU7U5]See here. Why would this have been done? I could see the point in blasting a channel right through a coral reef to allow ships through, but these holes don’t extend right the way out to open water, and there are loads of them. The only other explanation I can think of was removal of coral as a building material, but that seems rather haphazard for building a military base. ---
**Author:** ![Kobalt](https://avatars.discourse-cdn.com/v4/letter/k/41988e/32.png) [@Kobalt](https://boards.straightdope.com/u/Kobalt)\ **Post date:** [December 24, 2013, 1:41pm UTC](https://boards.straightdope.com/t/diego-garcia-base-what-are-these-rectangular-holes-in-the-coral-for/677075/2 "2013-12-24T13:41:51Z")
IIRC, crushed up coral was used instead of gravel to lay down a lot of the roads on Diego Garcia. That was quite a while ago, though, and I don’t remember seeing holes in the coral, but that could just be that after a while, I stopped paying much attention to the area. Beach, ocean, trees, rocks…120 days until I go home. Beach, ocean, trees, rocks… 119 days until I go home. Beach ocean, trees, rocks… 118 days until I go home. etc. etc. etc. ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [December 24, 2013, 2:02pm UTC](https://boards.straightdope.com/t/diego-garcia-base-what-are-these-rectangular-holes-in-the-coral-for/677075/3 "2013-12-24T14:02:36Z")
Are they holes or marks left by boats? ---
**Author:** ![slaphead](https://avatars.discourse-cdn.com/v4/letter/s/e9bcb4/32.png) [@slaphead](https://boards.straightdope.com/u/slaphead)\ **Post date:** [December 24, 2013, 2:03pm UTC](https://boards.straightdope.com/t/diego-garcia-base-what-are-these-rectangular-holes-in-the-coral-for/677075/4 "2013-12-24T14:03:30Z")
> [@Colophon](#): > > that seems rather haphazard for building a military base. Why? if they need landfill material they either need to ship in in from thousands of km away (slow and expensive), dredge it off the seabed (faster and cheaper but needs special equipment, may be loose sand and not suitable), or bulldoze it out of some part of the island (quick & easy). It’s not like there are any locals to complain about spoiling the beach. My guess would have been excavating fill for extending the land area. I think the original shoreline was along where the inner road runs (similar to how it is further along eclipse bay) and the area of the square harbour and large dock plus the CONEX ‘park’ was all built with landfill. Most material would have come from dredging the shipping channels but it would also have been easy to scoop some additional material from the coral shelf. Another possibility would be pushing material out towards the ocean to make a broader wave barrier and prevent storms pushing waves onto the island and flooding parts of it - but digging landfill seems more likely. ---
**Author:** ![Colophon](https://avatars.discourse-cdn.com/v4/letter/c/f05b48/32.png) [@Colophon](https://boards.straightdope.com/u/Colophon)\ **Post date:** [December 24, 2013, 3:54pm UTC](https://boards.straightdope.com/t/diego-garcia-base-what-are-these-rectangular-holes-in-the-coral-for/677075/5 "2013-12-24T15:54:20Z")
Hadn’t noticed I’d screwed up the tags there. [Here is that link again](http://goo.gl/maps/LU7U5). And yes, I suppose digging up coral is a good alternative to shipping in landfill. Don’t tell the greens! ---
**Author:** ![Amateur\_Barbarian](https://avatars.discourse-cdn.com/v4/letter/a/59ef9b/32.png) [@Amateur\_Barbarian](https://boards.straightdope.com/u/Amateur_Barbarian)\ **Post date:** [December 24, 2013, 5:21pm UTC](https://boards.straightdope.com/t/diego-garcia-base-what-are-these-rectangular-holes-in-the-coral-for/677075/6 "2013-12-24T17:21:48Z")
It’s obviously a bar code. ETA: Are those BUFFs on the hardstand? ---
**Author:** ![aruvqan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aruvqan/32/2891_2.png) [@aruvqan](https://boards.straightdope.com/u/aruvqan)\ **Post date:** [December 24, 2013, 5:47pm UTC](https://boards.straightdope.com/t/diego-garcia-base-what-are-these-rectangular-holes-in-the-coral-for/677075/7 "2013-12-24T17:47:30Z")
Could be worse - there are a couple of excavated areas on Cudjoe Key on the north shore where they dug out what appear to be a couple slips for boats - I am guessing that the area was some sort of former government property back in WW2 - the area is just east of the Blimp Station. Between Cuthroat and Blimp Roads. I like the one closer to Blimp Road, I figure that would be a great place to put up a house and finish up the cuts to have a safer mooring place for a boat. You would just have to put in a driveway, the sewage/water systems and electricity. It is part of a 5 acre lot which unfortunately seems to cost $5 million, so it is way out of our budget!☹ ---
**Author:** ![JBDivmstr](https://avatars.discourse-cdn.com/v4/letter/j/b4bc9f/32.png) [@JBDivmstr](https://boards.straightdope.com/u/JBDivmstr)\ **Post date:** [December 25, 2013, 4:24am UTC](https://boards.straightdope.com/t/diego-garcia-base-what-are-these-rectangular-holes-in-the-coral-for/677075/8 "2013-12-25T04:24:34Z")
> [@Amateur\_Barbarian](#): > > It’s obviously a bar code. > > ETA: Are those BUFFs on the hardstand? They sure [look like a B-52](http://en.wikipedia.org/wiki/File:GVG_B-52_Evolution_2.png), don’t they? ---
**Author:** ![the\_diego](https://avatars.discourse-cdn.com/v4/letter/t/7bcc69/32.png) [@the\_diego](https://boards.straightdope.com/u/the_diego)\ **Post date:** [December 27, 2013, 12:26am UTC](https://boards.straightdope.com/t/diego-garcia-base-what-are-these-rectangular-holes-in-the-coral-for/677075/9 "2013-12-27T00:26:46Z")
The relief picture is bad but I don’t think they’re man-made. They can’t be shoring works along the narrow portion of the island. They’re too irregular. They look like fracture patterns and other natural structures on the layer of limestone. I mean, why excavate near your man-made structures and leave them un-touched in the outward parts away from the facilities? ---
**Author:** ![Dag\_Otto](https://avatars.discourse-cdn.com/v4/letter/d/439d5e/32.png) [@Dag\_Otto](https://boards.straightdope.com/u/Dag_Otto)\ **Post date:** [December 27, 2013, 5:07am UTC](https://boards.straightdope.com/t/diego-garcia-base-what-are-these-rectangular-holes-in-the-coral-for/677075/10 "2013-12-27T05:07:00Z")
If they were natural, you would expect them to be present on the nearby islands to the northwest, but I don’t see anything similar at those sites. ---
**Author:** ![the\_diego](https://avatars.discourse-cdn.com/v4/letter/t/7bcc69/32.png) [@the\_diego](https://boards.straightdope.com/u/the_diego)\ **Post date:** [December 27, 2013, 6:23am UTC](https://boards.straightdope.com/t/diego-garcia-base-what-are-these-rectangular-holes-in-the-coral-for/677075/11 "2013-12-27T06:23:57Z")
OK, looking at the Egmont Islands, the two are very similar but for those rectangular shapes. Yes, they appear to be dredging sites. Just don’t know how you could quarry limestone blocks at sites that are alternately submerged every 12 hours. You have substantial earthworks on the north east side for the harbor and jetties. No need to double-handle whole blocks of limestone only to crush them. So now I believe they’re dredging strips. ---
**Author:** ![Rama](https://avatars.discourse-cdn.com/v4/letter/r/ccd318/32.png) [@Rama](https://boards.straightdope.com/u/Rama)\ **Post date:** [December 27, 2013, 4:12pm UTC](https://boards.straightdope.com/t/diego-garcia-base-what-are-these-rectangular-holes-in-the-coral-for/677075/12 "2013-12-27T16:12:50Z")
I think **Kobalt** already gave the correct answer. It was for roads. As seen [here.](http://en.wikipedia.org/wiki/File:The_O_Club_on_Diego_Garcia.jpg) I can’t imagine any other explanations. ---
**Author:** ![XT](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/xt/32/456_2.png) [@XT](https://boards.straightdope.com/u/XT)\ **Post date:** [December 27, 2013, 4:21pm UTC](https://boards.straightdope.com/t/diego-garcia-base-what-are-these-rectangular-holes-in-the-coral-for/677075/13 "2013-12-27T16:21:57Z")
> [@Kobalt](#): > > IIRC, crushed up coral was used instead of gravel to lay down a lot of the roads on Diego Garcia. That was quite a while ago, though, and I don’t remember seeing holes in the coral, but that could just be that after a while, I stopped paying much attention to the area. > > Beach, ocean, trees, rocks…120 days until I go home. > Beach, ocean, trees, rocks… 119 days until I go home. > Beach ocean, trees, rocks… 118 days until I go home. > etc. > etc. > etc. Pretty much this. It’s a hole and I couldn’t wait to get off of the island. Even Guam was better. ---
**Author:** ![slaphead](https://avatars.discourse-cdn.com/v4/letter/s/e9bcb4/32.png) [@slaphead](https://boards.straightdope.com/u/slaphead)\ **Post date:** [December 28, 2013, 10:55am UTC](https://boards.straightdope.com/t/diego-garcia-base-what-are-these-rectangular-holes-in-the-coral-for/677075/14 "2013-12-28T10:55:36Z")
> [@the\_diego](#): > > why excavate near your man-made structures and leave them un-touched in the outward parts away from the facilities? To get materials to for building your structures on/with? The coral islands I have been on were not notable for their broad expanses of solid, level ground, to put it mildly. > [@the\_diego](#): > > Just don’t know how you could quarry limestone blocks at sites that are alternately submerged every 12 hours. […]No need to double-handle whole blocks of limestone only to crush them. Uh, what? Quarrying? Double-handling? More likely just bulldozer + ripper, possibly with a bit of explosives. Or even just an ordinary backhoe with a special bucket like [these](http://www.digrock.com/). Coral rock is pretty soft and full of joints and flaws, its not like excavating through marble or something. ---
**Author:** ![Elendil\_s\_Heir](https://avatars.discourse-cdn.com/v4/letter/e/7cd45c/32.png) [@Elendil\_s\_Heir](https://boards.straightdope.com/u/Elendil_s_Heir)\ **Post date:** [March 10, 2019, 6:22pm UTC](https://boards.straightdope.com/t/diego-garcia-base-what-are-these-rectangular-holes-in-the-coral-for/677075/15 "2019-03-10T18:22:29Z")
Bumped. There’s a chance the US may lose its base on Diego Garcia: [Diego Garcia: Is the United States about to lose control of its secretive military base? | CNN](https://www.cnn.com/2019/03/09/asia/chagos-islands-feature-intl/index.html) ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [March 10, 2019, 6:52pm UTC](https://boards.straightdope.com/t/diego-garcia-base-what-are-these-rectangular-holes-in-the-coral-for/677075/16 "2019-03-10T18:52:06Z")
> [@Elendil\_s\_Heir](#): > > Bumped. > > There’s a chance the US may lose its base on Diego Garcia: [https://www.cnn.com/2019/03/09/asia/chagos-islands-feature-intl/index.html](https://www.cnn.com/2019/03/09/asia/chagos-islands-feature-intl/index.html) I assume we’ll be able to build a long term lease into any deal between Mauritius and Britain. The snag could be in allowing the original inhabitants of the archipelago to return after the [Brits forced them out](https://en.wikipedia.org/wiki/Chagos_Archipelago_sovereignty_dispute#Depopulation) so we could have the base. It’s not clear to me why they couldn’t occupy the rest of the archipelago. ---
**Author:** ![sps49sd](https://avatars.discourse-cdn.com/v4/letter/s/a9a28c/32.png) [@sps49sd](https://boards.straightdope.com/u/sps49sd)\ **Post date:** [March 11, 2019, 3:33am UTC](https://boards.straightdope.com/t/diego-garcia-base-what-are-these-rectangular-holes-in-the-coral-for/677075/17 "2019-03-11T03:33:12Z")
> [@TriPolar](#): > > I assume we’ll be able to build a long term lease into any deal between Mauritius and Britain. The snag could be in allowing the original inhabitants of the archipelago to return after the [Brits forced them out](https://en.wikipedia.org/wiki/Chagos_Archipelago_sovereignty_dispute#Depopulation) so we could have the base. It’s not clear to me why they couldn’t occupy the rest of the archipelago. There do not appear to be original inhabitants; the displaced Chagoseans were/ are imported workers or descendants of imported workers. My prediction- DG will remain a base. It is FAR too valuable to give up.