Perfect! That’s exactly what I need. Thanks for that.
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Any idea what triggers the mechanism with this contraption?
@ash2020 I’m really not sure but looking at that image LH side looks like a servo controlled lever controlling a release pin …RH side not sure some sort of receiver power pack prehaps ? …the self build guys on here might be able to help …Alan
Yes, I think so, but there isn’t a spare radio channel.
As they say - photos/video or it never happened … so I went out earlier to “re-enact” this bit of fun.
The landing was intentionally a tad “firm” … last thing I wanted to happen was the string to blow up into the props. 
Notice also the “quick release” that enables the “recipient” to easily detach the bottle. 
(Gotta love portrait video, too. 
)
Judging from the prop sound as the load increased … I reckon two bottles might be possible.
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Brilliant. I’ve been trying to get the guy at spitbank to let me try to deliver a pizza to him but he’s having none of it!!
Trying to find a guy with a large boat is plan b
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The weight of a pizza shouldn’t be a problem, but I’m not sure how things would work with something that shape in the prop-wash … without a long tether.
Range will obviously be compromised … but I’ve never tried hovering a whole battery’s worth of power with a bottle of beer on it, either. #NextTest 
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I was assuming the tether would have to be 4-5m long at least to avoid the effects. Also requiring weights on the line to avoid tangles after delivery…
I doubt it would need to be that long - another test needs to be done.
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Cool! Which is literally what the pizza will be.
The pizza has long gone! (And damned tasty it was, too! 
)
The aerodynamics of the box will be pretty much the same with, or without, pizza. I’ll put something in the box that equates to the pizza weight, though.
Gosh - 6 months ago that was!
Anyway … eventually got out with all the bits needed in the car at the same time. Forgot the string one time forgot I’t taken off the fixing pint when wrapping the Mavic Pro the other time.
First tether was only 120cm for the first clip, and no problems. Halved it for the second clip and it picked up some oscillations from the prop-wash … which I then exacerbated by miss-timing the correction.
Contemplated going down the 40cm … but decided against it.
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Just realised this is a 6 month old thread, hope you had some success xD
The polytube example someone posted above looks really good, if you want another option then consider these as well. The most common ‘remote’ water sampling methods we use are Niskin or Van Dorn samplers.
They are both basically a tube with open ends that have end caps which are sprung together in a closed position by some elastic, you hold these caps open with a wire, then release it at the desired depth and the caps spring shut, sealing the tube. This gets rid of the issue of buoyancy and crushing you see in air filled bottles.
You could probably build one with some kind of hydrostatic release, possibly something purely mechanical like a buoyant release, so once you’re in the water the buoyancy pulls a pin or something to snap the ends shut.
Hi there @Bobbysmile , I work for Yorkshire Water and we may be interested in getting some water samples from the Humber Estuary by drone during 2025 & 2026. Have you been successful in sampling such environments for commercial clients? Your sampler images look really good. Kind regards.
Hi, those are commercial products designed for use off boats (my background is as a oceanographer) and are the defacto standard for ‘at depth’ water sampling within industry. However they are both too large to fly from any reasonable size drone.
Depending on your requirements (sample volume, sampling depth, estuary flow rate) a miniaturised version may be suitable, they are not complicated devices.
Feel free to DM me some more specifics and I can advise, alternatively my contact info is available on my website which is linked in my profile.