21/1/06

Eventually got cruising again!  Took UH18 and Scout on finished double deck trailer to Berwick and launched into estuary behind harbour.  Sea was pretty rough so we didn't venture out there.  Cruised up river for about 20 miles.  River was in full flow (about 8mph in places) and very dirty - but smooth with no wind. 

It's been so long ago that I was on a hover I'd forgotten how much fun it is!  Both craft behaved faultlessly.  I have to travel pretty slow on the UH18 to let the Scout keep up - by adjusting lift I found I could cruise along at about 25mph with the engine at only 2200rpm very quietly.

 

10/2/06

Short cruise on river again - about 20 miles or so.  Flat calm water - both craft performed OK.  UH18 was running on a bit when turned off although it ran OK the rest of the time (I'll need to check the anti-dieseling solenoid).  On the smooth water I can get the UH to cruise along at just 2000rpm at around 25mph by controlling the lift enough to avoid skirt drag or spray.

 

10/4/06

Finally hit some good weather to test the Prospector on water.  I tried it at Berwick upon Tweed - launched from the sloping beach into the sheltered harbour bay.  the craft was excellent - no problems whatsoever.  It's a bit sensitive to steer probably as it's so big - the back end is a bit susceptible to over steer if you don't relax a bit!  I traveled up river for about 12 miles or so through some pretty narrow sections - once I got used to the steering it was absolutely fine.  The craft can be driven at about 12mph without falling off plane which is handy for negotiating tricky bits.  It planes out at about 10mph and will comfortably cruise at around 25mph and 2500rpm on the engine.  I did about 30 miles or so altogether and nothing broke or fell off.  

After returning to the harbour bay I couldn't resist trying it out on the sea.  There were 3-4ft waves breaking on the beach so I first crept along the sheltered harbour wall and ran into them from the sea (see Videos page).  Amazing fun - it's just like surfing - the waves pick up the hovercraft and accelerate it into the beach.  After a few runs like that I decided to see what would happen driving directly into the breakers - the craft just points it's nose into the air then drops into the following trough.  I am thoroughly impressed with the capabilities - at no time did it feel unstable or unsafe.  In fact it is more comfortable than a boat as you come down off the waves onto an air cushion rather than crashing into the water.

The pic below shows the contents of the cabin - an inflatable boat with an outboard, paddles and a box of engine spares!

Nothing like expecting the worst!  You can also see the fold down hood I made this week - it folds back against the rear seat back and clips to the top edge of the windscreen.  As it didn't actually rain today (a bit of a novelty this month!) I didn't get a chance to test it.  The hood is made from 260gm/m2 (9oz/yd2) PVC coated mesh and is simply glued together at the joints.   And, yes, that is a carpet on the floor!  It's an outdoor grade carpet as used on golf ranges, etc - it is completely porous, rot-proof and UV protected!

Craft noise didn't seem bad at all.  In the cabin area all you can hear is the propeller chop - the fans are virtually silent.  If you sit on the rear bench seat you can't hear the prop and it's very quiet.  Outside the craft you can hear the prop most of the time and the fans when the rear end is pointing at you (a bit of a whining noise).

Maneuverability is excellent at slow speed - I managed to turn the craft 180 degrees in a space between sand dunes the same length as the craft without any external pushing and shoving!

The only downside to the day was the trailer - I managed to bend one side at the back end.  The trailer wasn't dead level and the craft rode up and over one of the sloped sides.  The full craft weight was then taken on the slope and the centre of the deck - both these areas are lightweight structurally and can't take that load.

15/4/06

Met with Trevor and his Osprey 5 at Musselburgh on the Forth estuary.  Hovered up and down the coast for about four hours or so.  Sea was very choppy in places and flat calm in other areas.  Both craft performed well in the rough conditions.

23/4/06

Went to Berwick with Prospector and met with Peter - launched from usual spot.  Weather was sunny with a 10mph wind - perfect conditions. Sea state was slight so we traveled about a mile down the coast and back before starting a cruise upriver.  We traveled up river for about 20 miles past Coldstream.  We had to negotiate couple if biggish weirs on the way - one at Coldstream was about 20 feet wide 30 degree concrete slope with a 12 foot gap in it though which the entire river was flowing.  Luckily the river was still high so the drop off on the upriver side was only a few inches so we just ran up and over the weir slope.  

The craft was faultless and behaved perfectly.  The low speed handling is superb as I found out after taking the wrong turn past river islands a couple of times and ending up negotiating a route through 12 ft wide tree lined streams with boulders and bits of tree sticking out!  I still have a funny squeak from the engine area that I've been unable to work out the source.  It sounds like two bits of metal rubbing together  and seems to disappear when the engine speed increase - maybe it's a mouse;-)

View approaching Coldstream bridge - the concrete weir was about ten yards this side of the bridge

Peter and Matt enjoying the benefit of a heater when the sun disappears :-) . Matt is making a mobile call while driving - that's what I call relaxed cruising!

We spent a great deal of time standing up in the craft - sometimes all three of us were leaning over the windscreen looking at the view!  It seems to be very insensitive to fore and aft trim - it doesn't matter much where the load is.  It is more sensitive to side to side trim though - in fact it helps quite a bit with steering if you step sideways a bit while turning (this surprised me on such a large craft).  On the sheltered stretches of river I could cruise along at about 2200rpm and stay above hump speed (about 12mph or so).  On rougher bits into the wind I needed about 2800rpm to keep reasonable headway.  We were hovering for about four hours, traveled around 54 miles and used a miserly 22litres of fuel (just under 5 gallons).  In fact I had to keep checking the fuel level as it didn't seem to be moving much!  The low fuel consumption was probably down to the leisurely pace - a lot of the time it was barely 15mph.

5/5/06

Took UH18 and Scout to Berwick this afternoon/evening - beautiful day, sunny and warm!  Both machines performed fine although the UH18 lift fan was occasionally striking the duct depending on how the hull flexed.  Sea was very rough so we only went about 20metres off the beach - the waves were just tossing the craft around and you have very little control when a wave grabs the craft - it felt safe enough though as the local lifeboat was on exercise just a couple of hundred metres offshore!

11/5/06

Went to South Queensferry with Trev and launched onto the Forth under the rail bridge.  Weather was very warm with virtually no wind and sea was almost flat calm.  We crossed to the Fife side and traveled out to Kirkcaldy (about 23miles),  Stopped at Inchcolm Island on the way back before  giving a ride to a couple around the Forth rail bridge piers.  Hovered for around 49 miles.  The weather conditions suddenly changed for the worse in late afternoon - the wind got up and, within 15 minutes or so, the sea had turned from flat calm to white caps with 3 ft chop in places!  I burst the front curtain skirt hull attachment from one side (screws and attach strip came off) due to the sudden pressure increase as the bow dropped into wave troughs.  The craft performed fine even though the skirt was loose at the front - I didn't even notice it until we were back on the pier slipway.  The only other problem was with the engine which seemed to lose power occasionally - I suspect that there is either a carb problem or it's water on the ignition system.  It only seemed to do this after a stop on water.

Inchcolm Island (about 5 miles off shore), has an 10th century Abbey - and a tourist shop of course - two hovercraft and no people!

Launch ramp at Hawes pier with the 1.5 mile long Forth road bridge in the background (the reflection in the water shows how calm it was at this point)

21/5/06

Went to Berwick again - weather was cloudy but cool.  Traveled south offshore for about 4 miles or so around a rocky outcrop.  Sea had a 2ft swell with chop on top - particularly rough around the rocky bit.  Water was very clear and you could see clearly the underwater rock formations as you hovered over them.  It wasn't a very comfortable ride - especially on the way back as we were also heading into the wind (see Videos). 

Did some surfing onto beach and then hovered up river for around ten miles.  Wind had picked up to around 15mph at this point making downwind runs a bit tricky on the steering as the craft tends to want to swing in line with the wind like a weather vane.

4/6/06

Went to local vintage car show with all three craft (and Trevors Osprey5).  We had the use of the field where the trailers were parked.  It was very busy - the hovercraft attracted a lot of interest and the time passed very quickly. 

We were unable to give rides (much to the disappointment of the public!) as we couldn't get insurance cover from the event organisers.  We did run the craft in the field - avoiding the helicopter approach path and the sheep!

9/6/06

Visited Keilder water in Northumberland after getting consent from the water company to test the Prospector.   The water has an 8mph speed limit but they allowed me to use an area set aside for water skiing to do "speed trials".  Craft was perfect - I did around 28miles in a couple of hours.  It was a bit windy when I got there with 6" chop in exposed places - by the time I came back it was 3ft chop!  The wind speed had increased to about 18mph so I needed a fair bit of power to make headway against the wind and chop.

The road to nowhere!

Kielder is a man made reservoir made by flooding a valley - it still has various old roads and fences that disappear underwater at the edges - the centre is around 200metres deep with a small village underwater along with farms and fields.

I did several speed runs up and down the water ski zone and got an average of 44.6mph.  the conditions were less than ideal with the wind blowing at right angles out of a valley half way along the run - the craft would do a sudden 20degree turn to one side every time you crossed the valley exit!.

One thing I did notice for the first time is that the skirt brake doesn't work very well at all at speed - you get very little pitch change even with the vents full open.  I suspect that the problem is caused by the fact that the vent ports are trying to expel air directly forwards against the oncoming air stream - obviously harder to do when the craft is traveling fast.

2/7/06

Visited Berwick again.  Weather was very warm (26C) but turned very thundery late afternoon.  Cruised up river and in estuary.  The wind picked up later to about 20-30mph.  As I turned the corner on the sea around the breakwater the wind pushed the craft onto the shore - I couldn't turn into the wind at all!  I had to do a 180 and use thrust to stop - during the 180 the wind was so strong it pushed spray back through the prop into the engine and made in start to cut out.  We got blown back onto the beach in a very short time.  It's quite amazing the effect of a strong wind! 

The boys were diving off of the moving craft into the river to cool off!

17/7/06

Decided to take Scout to coast to try out new 21hp engine on water (very hot day - too hot for work!).  Took double deck trailer with Scout and UH18.  About five miles from the coast disaster struck!  The front tie strap holding the Scout to the upper deck failed.  The 50mph forward air flow then rotated the Scout hull to nearly 60 degrees (the front plough plane certainly helps with this!) and broke the rear ply top deck.  This deck then bent the UH18 roof and the Scout engine frame legs then pushed down on top of the UH18 duct until it fractured in three places - what a mess!!

The good news (yes - there is some) is that, other than a slight crumpling of the bottom of the rudders, the Scout is unharmed.  It's amazing how strong the back end is as it's just been used as a giant air-operated lever!  There is evidence that the hull flexed a bit as the side aluminium skirt strips have a slight ripple at the pivot point but, after careful examination of the hull, I can't find any soft spots or cracks.

I had to remove the rudders and trim wing from the UH18 at the roadside as the top mounts were only just still attached to the remains of the duct.

I can't really face re-making the UH18 duct - it's a major job.  I will probably just fit a mesh/tube guard - not as pretty but it shouldn't affect performance too much hopefully.

18/7/06

Took Scout on big trailer to Paxton on river.  It was 31C and still when we left but it was only(!) 24C at the river side - there was also a 20mph+ east wind blowing directly up the river producing 9" waves and chop.  Not the ideal kind of conditions to test a new engine installation!  We launched anyway and were pleasantly surprised by the performance - there is plenty of thrust both up wind and down wind (see videos). 

The engine is actually quieter than the Tecumseh but there is a bit more prop noise at higher rpm (sounds like a light aircraft taking off - not surprisingly!).  The wind was so strong it was causing the bow to dip when traveling downwind - not really a problem as it just activates the brake.  The overall maneuverability is also much improved as you have extra power available to turn easier.  We clocked 34mph on the GPS - the craft would have gone much faster but the wind didn't make it feel very safe!

28/7/06

Visited Berwick solo and cruised up river and back for about 18 miles with Scout.  River was very low and several side channels I normally use had no water in them.  The scout was fine apart from the rear skirt drag problem that seems to have re-surfaced.  The back end skirt is also scooping water up into the lift duct of you chop the throttle at moderate speed - it doesn't sound very good when the lift fans hits water!  I need to look again at the back end skirt shape.  The water was very choppy on the return trip in one area as the incoming tide flows up river.  I have also decided to reduce the prop pitch to reduce thrust at lower speed to give better control.

8/8/06

Berwick once again with Scout and Prospector - this is getting boring!!  The problem is that it is a good location as you have the choice of environments - river, bay or sea - depending on the conditions at the time.

This was the first outing with the Scout hull on the roof of the car - the air drive was sat on the floor in the Prospector.  The Scout hull didn't seem to affect the car at all which surprised me - it must be more aerodynamic than I thought!

The Prospector engine was playing up a bit - it wouldn't hold mid throttle without dying.  The idle was fine and when the second choke opened it was also OK so I suspect that there is a blocked jet or other muck in the carb.  It was difficult to drive as you could either have full power or nothing!  The sea had breaking waves on the beach but looked smooth - unfortunately it wasn't.  It had a short swell with fairly deep troughs (about 2 ft) and an irregular pitch - very uncomfortable!

18/8/06

Spent the last five days camping on the banks of Loch Lomond with Scout and my boat (see videos).  Loch Lomond is the largest freshwater Loch on Scotland at 24 miles long (and up to 5 miles wide).  The weather was very good for hovering - less than 7mph winds and warm.

  

The Scout performed faultlessly and we managed about 3-4 hours hovering each day.    The 17ft boat with a 60HP engine couldn't keep up with the Scout!  It also consumed about ten times the amount of fuel!  A couple of times I had to drive back against some fairly rough chop and a strong headwind (15mph) - although it's not that comfortable it's safe enough if a little slow - I'm glad I upgraded the engine as it now allows reasonable headway into wind.

The Lomond1 video shows how maneuverable the Scout is - you can turn circles on the spot in water - you can see that there isn't that much spray - although then tenth successive circle resulted in the drive belt getting wet enough to slip a little - the first time that's happened!  You can also see about half way through the clip the front brake being used (the nose drops) to slow the craft before a sharp left turn back to shore.

Above pic shows Scout sitting on a gravel bank about 1/2 mile offshore - the bank is marked as a boating hazard for obvious reasons!  Only about a 1ft by 4ft strip was above water - and only just - so the Scout nose was "parked" on it and I couldn't get far enough away to get a decent picture!

9/9/06

Met with Trevor at Bo'ness on the river Forth (see videos).   Launched from slipway onto mudflats with tide coming in.  We cruised downriver past the Forth bridges and around a large cruise ship (the Mona Lisa - nice painting on the funnel!) that was anchored in the middle of the estuary.

There is quite a lot of traffic on the river - several large cargo ships went by - also tugs and smaller sail boats.

The weather was excellent - sunny and warm with 6mph winds.  The sea sate was also very good - it was a bit choppy crossing over at the wider point but very smooth for the rest of the time.  The wash from the large ships was interesting - very deep but very long wavelength - like riding up a hill then down the other side!

After hovering on the east coast I then drove across to the west coast to stay at Loch Fyne - a 40 mile long sea loch.  We launched about four miles south of Inveraray and cruised around the Loch until sunset.  Water had a little chop and a small swell as the tide was coming in.  At first I couldn't work out why the tide time was different to the east coast I was on a couple of hours ago - I then realised that it has to be coming in on the east coast of a sea and going out on the west coast at the same time!

Parked up on a boulder beach for a bit of exploration!  I was impressed with the size of boulders the Prospector would hover over - The lower part of the shore had the boulders entirely covered with seaweed  making it impossible to walk over so we had to get a bit higher up before stopping.

Sunset over Loch Fyne - the wind had dropped by this time and the water was very smooth.

 

10/9/06

Still at Loch Fyne (see videos)  - the weather was great again - very cool early morning but no wind until mid day.  The water was like a mirror early on

Sunrise looking out over Loch.

I bet it doesn't get much smoother than this!

Parked on shore just below Inveraray Jail (16th century jail and court complex open to public - well worth a temporary(!) visit).

You have to be careful of the tides here when parking up on shore - it's so far from the open sea there are no waves to remind you that it is the sea - it just slowly fills up and drains like a bathtub.

18/9/06

Met with Trevor and his Osprey5 at Berwick.  We launched into harbour bay and cruised up river for about 18 miles or so past Coldstream.

Parked on an island near Norham castle (top left).

Parked on a weir at Coldstream bridge right on the English/Scottish border!  The river is half England, half Scotland from the bridge on the left almost down to Berwick.  The pic was taken standing in Scotland looking to England and upriver from the bridge (to the left) is all Scotland - aren't borders really stupid!!

After returning to the harbour, we decided to have a play around on the sea.  There were huge breakers coming in and a big off shore swell (4-5ft) so we stayed close to the beach.  After about 1/2 hour or so Trevors craft broke it's main drive belt - he took al small amount of water through the fan from a breaker (see  videos).  The belt must have been dodgy as there were no broken fan blades.  Unfortunately, it broke about a mile along the beach!  Luckily, the tide was coming in so the craft slowly got washed further in.  At this time, the Coastguard turned up in a 4x4 - they suggested driving the trailer along the beach and pulling the craft onto it.  After attempting this, Trevor got stuck in the very soft (and deep) sand  - the Coastguard 4x4 also had to be pushed out of the sand.  The local inshore lifeboat crew then turned up just to increase the size of the crowd - followed by the off-shore lifeboat crew!  There were now plenty of ideas as to how to recover the craft!  Eventually the lifeboat guys just floated the craft in the surf and pulled it along the beach towards the car park.  The car and trailer were then manhandled down the beach into the water and the craft loaded.   With the help of about 20 people, two 4x4s and a lot of rope and sweat, the trailer was pulled up the 20 degree beach slope into the dunes and eventually up onto roadway (it took two hours to do this!).     I would like to thank all of the RNLI and Coastguard guys (and gals!) and any unidentified others who helped - they didn't really need to as there was no danger to life in the situation.  There are a few lessons here - you can't  drag a small wheel trailer on soft sand - it doesn't matter how good your 4x4 is!  The second lesson is that, if you have to breakdown, make sure it's in a public place with loads of helpful people around!

I had problems re-loading my craft in the dark.  Finding the narrow sand exit ramp (next to a disused pier) was the main one.  Although the visibility on the water was OK, the shoreline was just a black mass.  You couldn't really make out where you were until about 15 metres away - too short a distance to build up enough speed to get up and over the ramp.  After a few abortive attempts I eventually just went for it hoping I didn't drive straight into the pier - maybe a headlight would be a good idea after all!  All in all an interesting day - got home about midnight!

1/10/06

Went back to Berwick and cruised up river again past Coldstream with Scout and Prospector.  Weather was very warm (for the end of September in Scotland that is!) and sunny until we reached Coldstream when black rain clouds started to build up.  The skies opened on the return journey and I got a chance to test the Prospector hood!  It worked fine although I did have to take pity on the Scout driver and stop to take shelter for a bit!  Both craft were perfect - no problems whatsoever (short videos of Scout and Prospector here).

This was the first water outing with the Scout since I changed the pulley/prop ratios (they are now back to the original larger pulley and 14 degree prop pitch).  The craft is now very fast and hits 35mph with ease - under full power it accelerates very rapidly.

4/10/06

Visited Paxton and cruised on river for a couple of hours with father-in-law and brother-in-law - first hovercraft trip for both of them.

9/12/06

Back to Berwick and upriver again.  The river fishing season has finished until February so we traveled upriver almost to Kelso (about 30 miles).  Temperature was 4C so we were glad to have a heater!  Wind was about 15mph downriver making upriver progress a bit leisurely at about 18mph - downriver speed was around 33mph at 3000rpm.  Used around 30litres fuel (6.5 gallons) in 2.5 hours continuous cruising.  Craft was perfect apart from a intermittent miss on the last part of the return journey - I suspect a bad spark plug (again!). 

Sunset over river - at around 3:30!

See videos and picture library for images.

Additional information