tisdag 10 maj 2011

Why the Waterbuoy can't be trusted

Short summary for you who don't have the time:

Bought four of theese



in order to prevent this



from sinking if it should crash into the water. But since the Waterbuoys didn't work (as showed by several youtube clips)

I had to pay 500 € for this



which didn't make much sense anyway since all the electronics where destroyed after 48 hours in the water. And that's 5 000 € worth of electronics.

Waterbuoy/Seatriever first tried to disclaim their responsibility for the malfunction of their safety gadget my proposing that the propellers might had popped the balloons. They have stopped responding to my emails, and that's a shame. With this page I hope to warn everyone who might consider attaching any valuable item to a Waterbuoy. They just don't work.

The long story

RC helicopter drops into the sea
OK, don't people have better things to do than starting blogs about safety products that don't work, you might think? Well, read my story, and you might understand my frustration over having 5 000 € worth of equipment destroyed due to the malfunction of the famous Waterbuoy.

I run an aerial photographing business, where I use radio controlled helicopters to make cameras fly. Flying over water is always nervous, because now and then these things come down, and electronics and water is a bad combination. For this special mission, where I was filming a sailing boat, I had bought four pieces of Waterbuoys, that, according to the products specs sheet would keep an item with the weight of 4 kg afloat. Since the system I used weighs 3,5 kg I felt quite assured that it would not sink, should the helicopter drop into the sea.



Well, of course it did. Having operated this kind of machines for a year, I've only had two unexplained power cut offs, and this was one of them. Of course it had to happen over water. Anyway, trusting my Waterbuoys, I expected the heli to reach surface within seconds. We had two boats in the water, ready to pick it up. But it never came emerged.

When electrical components connected to a power source get in contact with water, the metals start to oxidize, and that's what destroys the electronics. If you quickly disconnect the power and rinse the gear in fresh water, even cell phones and laptops can come out undamaged after some careful drying. And that's the whole idea with making the heli able to reach surface – to quickly recover, disconnect and rinse. The electronics on this very special type of heli (Mikrokopter) are not enclosed in any housing, and can therefore easily be rinsed and sprayed with anti corrosive oil in, which makes the outlook to save it quite bright if you only act fast enough.

The recovery
This happened far out in the Stockholm archipelago, and it took me 48 hours to get a professional diver out there. He found it on 20 meters depth, charged me 500 €, and said this:

"As I spotted the helicopter, I could see that two of the balloons where significantly smaller than the other two. About 1/3 of the size. It was obvious they hadn't inflated fully. After having reached the surface, I noticed how the smaller balloons slowly increased in size. Of some reason, the gas cartridges must had failed to inflate them when they where exposed to the water pressure at the current depth."









After careful rinsing, disassembling and spraying with anti corrosive, I send the parts to the technician that build my machines. He had been quite optimistic about the repair, but when he got the parts he was totally dejected. After two days in water with a connected battery, they where all completely destroyed.

Waterbuoy's respond
Now, the annoying thing about this story is the way Waterbuoy/Seatriver tries to disclaim their responsibility for the balloons. The whole mail conversation is pasted further down on this page, but here's a summary. They:

*won't comment the fact that two of the balloons had not inflated fully
* keep asking about the exact volume of any hollow part of the helicopter that's not sealed
* have stopped answering my e-mails

The most interesting thing is that they expect the customer to check or measure the exact inner volume of the item that's attached to the Waterbuoy. According to their logic, a 0,7 kg non waterproof camera that has an inner volume of 0,4 liters (very strange camera, just an example) will drag the balloon to the bottom because the total weight will exceed 1 kg when filled with water.

The e-mail conversation
Dear Seatriever team,

Facing a challenging task, I purchased four Waterbuoys as a safety precaution. They where attached by the four legs of a 3,5 kg RC helicopter that carries a HD video camera. The gear is 100% professional and is used for shooting TV programs and commercials.

Today, despite all odds, what just couldn't happen happened. While hoovering above water, motors lost power and the heli plunged into the Baltic sea. Confident that I had attached Waterbuoys with a total buoyancy of 4 kg:s, I waited for the it to reach the surface. But so did not happen.

My question is: What can you do for me?

Regards

Ulf G

Their reply:

Dear Ulf

Thank you for your email which I forwarded to our Head of Technical and for bringing this to our attention.

Below is the response from our Head of Technical that you may wish to reply to:

1. How were the Waterbuoys attached to your helicopter?
2. Was the total assembly of the helicopter only 3.5kg?
3. Was the helicopter watertight?
Technical theory 1: The Waterbuoys could have become detached when it hit the water
Technical theory 2: Your helicopter had a mass of more than 3.5kg.
Technical theory 3: If the Cabin and other structures of the helicopter was not watertight, and the assembly did take in water as it sank, this would have increased the mass of the assembly (helicopter plus water volume), which could have increased the effective mass to be lifted by the 4 fitted Waterbuoys above the limit of 4kg. Furthermore, the irregular shape of the helicopter, possibly with its cabin door/window broken could increased the drag effect (water resistance) , and this could have increased the effective mass that the Waterbuoys would need to lift.
An alternative theory...
4. When the helicopter hit the water, were the blades of the helicopter still rotating? If so, did the rotating blades cut, hit or damage the case of any of the 4 Waterbuoys? I ask this because when a normal helicopter goes down, the first thing that happens is that the cabin of the helicopter breaks into (usually) two pieces, but the rotating blades continue to have momentum and continue therefore to rotate. As a result they chop up anything that’s in their way – usually the unlucky passengers... Obviously your model helicopter had no passengers, but the rotor of your helicopter would have continued to spin as it entered the water and may have chopped one or more of the Waterbuoys in half... or detached one or more of them).


I look forward to hearing from you again,

Kind regards

Hannah

Me:

Dear Hanna,

Thank you for your reply. Things got clear as the professional diver I hired found the helicopter at 20 meters depth this Saturday. I've attached some pictures. Quoting the diver: "As I spotted the helicopter, I could see that two of the balloons where significantly smaller than the other two. About 1/3 of the size. It was obvious they hadn't inflated fully. After having reached the surface, I noticed how the smaller balloons slowly increased in size. Of some reason, the gas cartridges must had failed to inflate them when they where exposed to the water pressure at the current depth." Myself, who was maneuvering the diving boat, also noticed that two of the balloons where not fully inflated when they reached the surface. The image with the diver in it was taken as we reached the shore, and by that time all balloons had inflated. Note how the inflated buoys easily keep the heli afloat (this can also be seen in this video, where the two balloons at the far end actually still look a bit smaller than the two closer to the camera ). So the weight calculations should be alright.

I've got no doubts that you'll understand the seriousness in this. Flying above water includes a calculated risk – and the condition to do so is the possibility of a quick recovery should the gear drop into the sea. A quick pickup, immediate disconnection of the batteries and rinsing in fresh water would have saved most of the electronics. Now they ended up in salt water for 48 hours with batteries connected, before we could get a diver out there. That wrecked most of it. I don't know the total repair and replacement cost yet, but it will start around 1600 €, part from the diver who charged 500 €. This is a severe strike to my business, and I never would have taken this risk if I had not trusted the Waterbuouys.

Kind regards

Ulf G

Me again:

Dear Hannah,

The metal bars have a total inner volume of aprox. 320 cm3. The landing legs are hollow as well, they have a total inner volume of 12,6 cm3. So all together it would be 3 500 g + 340g = 3 840 g.

Kind regards

Ulf G

Me again:

Dear Hannah,

It seems like our dialog has halted somewhat. I'm looking forward to a reply from you.

Kind reagrds

Me again:

Dear Hannah,

I still wait for a reply from you. Judging from the earlier mails in our conversation, you consider the customer responsible for checking the exact inner volume of the item to be attached to the Waterbuoy ? For example, if I would wan't to use your product with a 0,7 kg camera, I would need to somehow measure the inner volume to ensure that the total weight, when the camera is filled with water, does not exceed 1 kg?

Please get back to me. I find this lack of response quite nonchalant in contrast to the problems and costs that has hit me due to, as I consider it, malfunction of you safety product.

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