« Reply #42 on: May 22, 2022, 1:11 pm »
 
I will not hesitate to remind you of that statement, and will hold you to it by whatever means necessary.

« Reply #41 on: May 22, 2022, 12:53 pm »
 
I shall be "trying".
I hope thats enough. ::)
Memories are BETTER than Dreams---"Capn" FLINT

« Reply #40 on: May 22, 2022, 11:16 am »
 
... and will remain chastened and silent for many months. ::)
Really?  ;)


BTW it wasn't Jane  :o

« Reply #39 on: May 22, 2022, 9:20 am »
 
Ah- I get it. THAT is indeed ME but im in YOUR Otter - see three bladed thrust, rather than MY 6 blades.
THAT (from whats left of my memory) was when my new B+S engine dropped a valve seat and you kindly lent me your OTTER?
I categorically take back my unsound (nay reckless) accusation over video colour palette tampering and will remain chastened and silent for many months. ::)
Memories are BETTER than Dreams---"Capn" FLINT

« Reply #38 on: May 22, 2022, 9:13 am »
 
John, Im sure that last craft- yellow otter is me and Jane in MY craft? which was WHITE?
Have you doctored this clip so it looks YELLOW?
Just asking!  ::)
Memories are BETTER than Dreams---"Capn" FLINT

« Reply #37 on: May 22, 2022, 8:59 am »
 
Lessons were learned more than ten years ago after Keith first demo'ed his innovative gear (I first saw it back in 2009 from memory).  In reality, it just demonstrated what should have been glaringly obvious with hindsight - in that anything in the intake air stream that produces turbulence WILL make noise when the turbulence is hit by the rotating things.  Two obvious ways to reduce the noise: 1) clean the intake or 2) reduce the energy (via speed or diameter) in the rotating device (less energy = less noise). 

Both of those things were primary design goals for the Otter (and other craft) and resulted in a very quiet craft (other stuff like engines and exhaust can be easily silenced) but it's harder with air moving devices that, by their function, can't be covered).  The Otter "prop" intake is almost completely clean which makes it very quiet - evidence here (red craft is a BHC Marlin with a claimed noise level of 78dBa @ 25m, yellow is an Otter):

https://youtu.be/pUpXjM9J83g?t=261

« Reply #36 on: May 21, 2022, 7:53 pm »
 

« Reply #35 on: May 21, 2022, 7:52 pm »
 

« Reply #34 on: May 21, 2022, 3:59 pm »
 
An even better article by Keith on Youtube:  Teck Talk-Keith Oakley-Quiet Hovercraft
Clear video examples of the work and research. Regards, Francois

« Reply #33 on: May 20, 2022, 8:52 am »
 
I managed to dig up the article by Keith Oakley, he worked on this for many years and in the end the modern computer gave a useable "picture" of our problems. Regards, Francois Malan

« Reply #32 on: May 20, 2022, 7:26 am »
 
We are of course all welcome to our opinions and on this subject I would need to disagree  ;)

I've operated on the Severn estuary and Bristol Channel mud from Longney Crib where it first appears to Stert Flats beyond Burnham on the English side and Newport on the Welsh side. All are different, and hazards vary, but  there are none that exclude a SEV for any reason. I've operated all my craft from Weston, from an Osprey 1 through a Surveyor and the Otter , and there are no hazards that a decent pilot can't cope with.

Nor would I agree with the implications that the SEV skirt is more prone to damage than a segment skirt. Rather, lacking snagging points, it rides over potential snags, always provided its kept in good condition.

Even when damage is sustained, it can cope with remarkably large tears - up to 6ft of contact line can open up and it still flies - with a bit of a list, mind, but enough! In field repairs are easy too - just stitch it up with tie wraps, but its a very rare occurance.

The SEV structure is light of course, due to its advanced (relatively!) construction of foam core composite. However, this structure provides much better strength and stiffness for a given weight than does a traditional fiberglass structure. Of course, if you run it into an iron girder at 30mph it will likely cause damage - so best not to!

So there's a good deal of personal preference here in choice of craft, and that's all good,  but theres no reason why a decent pilot cannot operate a SEV at Weston.

And that concludes the case for the defence your honor  :D
Ian Brooks
Gloucester, UK

« Reply #31 on: May 20, 2022, 7:10 am »
 

So
Keep a good lookout and operate in a sensible cautious manner.
I also understand that a license is required to operate there too.
I also understand it is very very icky and muddy.


Ross come to Loch Fyne just once, it’s clean and beautiful with Pristine beaches and loads of immaculately clean water…….it’s also got Pubs…..right on the beaches.
If you come once………you’ll come again.
The company is not bad either
You can also bring your dog,we have hover dog Polly.

« Last Edit: May 20, 2022, 7:23 am by Ronnie L »

« Reply #30 on: May 19, 2022, 11:16 pm »
 
You can use a Sev or any other reasonably quiet craft.  Sevs are superb for sea work, but we have a lot of obstructions on the mud flats that will rip skirts and potentially damage a lightweight hull.  All depends on what you are doing.  If you are launching at high water then not an issue as you will be off the beach and away.  Low water with half a mile to the sea or needing to run along the tide line, as we have to at times, is a bit different. Unless you have experience of operating in the area it is difficult to understand the issue involving obstructions, particularly wartime stuff that sticks out of the surface just a few inches.  Rather like drop off ledges but with hull ripping added into the mix.  Remember, I've had both types of craft.  I loved the Sev which I rebuilt but the BBV was better suited to the local conditions in my experience.


No training on the beach at Weston !  That would go against all the agreements for responsible use.  We have other sites in the area that can be used, but training on a public beach would go against what the club stands for and cause a lot of problems as well as getting you banned. 


Hope that explains the issue.

« Reply #29 on: May 19, 2022, 12:42 pm »
 
Hi Ross
Must remember that where you are is definitely not suitable for Sevs.
I thought John and Ian and possibly some of the others had been to your part of the world in the past.
I also thought you did training there?
Ah well……that’s a shame.

« Reply #28 on: May 19, 2022, 9:39 am »
 
Francois
When all the research has been done.
What you have just described is a Sev…….except a Sev doesn’t require a lift engine at all.
Don’t want to turn things into a hover makers argument, but that is absolutely what has been described.