Do tides affect hovercrafts?

[Vara]

I was a bit sceptical about this claim until I looked up some flight times

16:00 Depart London (LHR)
18:50 Arrive New York (EWR)
Wed 13 DEC
VS001 Economy
lowest Y
18:50 Depart New York (EWR)
06:40 Arrive London (LGW) + 1 day
Wed 13 DEC
VS3118 Economy
lowest Y

2hrs 50 London/ New York
11hrs 50 New York/London

I've noticed a similar disparity on cross channel ferry times but this is a bit harder to understand as ferrys go north/south so it must be some sort of leeway causing the 1 hr difference.

 

[stevebrassett]

[ QUOTE ]
I was a bit sceptical about this claim until I looked up some flight times
2hrs 50 London/ New York
11hrs 50 New York/London


[/ QUOTE ]
With 5 hours time zone difference, this gives 7hrs 50 minutes London/New York,
and 6hrs 50 minutes New York/London. Sounds about right, given the prevailing winds.

 

[jfm]

Yup, that's 7 hours 50 to NY, 6 hours 50 on the way back. AND the return flights often arrive 30mins early because of tailwinds

I did London-US-NZ/Oz return last week and the speed over ground indicator that they now have on your movie screen varied between 440mph and 600mph, yet the plane was a pretty constant 550 airspeed i think

The Sydney-Auckland timetable typically has a near 1 hour difference between outward and return, which I can't understand as it's only a 3 hr flight. Whereas 3-4 hour European flights (London Moscow, say) don't... :-/

 

[sarabande]

I like them muchly ! Very neat that the designers have got the power units to thrust over the top of the wings, so that the lift is increased, and also they're out of the spray zone.

 

[Lakesailor]

You've impinged on the renowned "spatial awareness" problem that women have. /forums/images/graemlins/smile.gif

 

[DPH]

[ QUOTE ]
Alright, let me put it another way. You're doing 20 knots on the GPS across water in flat calm conditions, no wind, no tide.

1/2 hour later there's 3 knots of tide against you. Nothing else has changed. Is your GPS still reading 20 knots, or is the fact that the surface you are travelling over is now moving against your direction of travel at 3 knots having an effect?

[/ QUOTE ]

Easy, you say nothing else has changed therefore you must still be doing 20 knots.

 

[DPH]

Then again, if it was flat calm with no wind and no tide and later there was a 3 knot tide then there must be either a 3 knot wind in the same direction to remain flat calm or the sea state would now ripple due to an apparent 3 knot wind.

Therefore your statment that nothing else has changed cannot be true.

 

[Stoaty]

Look it's all a waste of time. You can never measure the speed of a small hovercraft properly as they NEVER go in a straight line.