Buying a second hand hovercraft - some advice.

added by Emma on March 29, 2017 at 07:09

General Advice

In this chapter of our hovercraft buyers guide one, we’ll examine what to look for when buying a used recreational hovercraft. Over the years, lots of hovercraft manufacturers have come and gone – some producing great hovercraft…some less so. Even some current models are pretty poor and have quality or performance issues so you do really need to be careful. A used hovercraft that was junk when it was new…is still junk after 6 months or 6 years! The same applies to home-built hovercraft that come onto the market – even given good plans, the build, component quality, and specification vary enormously.

Just like when you buy most vehicles, your options are to buy either privately, or from a business. It’s likely that buying from a business will be more expensive but your purchase should come with a warranty, basic training and support, and being covered by consumer law, is probably a safer option for inexperienced or first time owners.

Just like we said in the initial part of this guide, the first thing you need to do is to decide what you want to use the hovercraft for. Is it for playing around a grassy field? Or cruising on salt water estuaries? The demands of the marine environment is significantly more and generally, a properly prepared cruising craft will cost more money than a basic machine to provide fun playing around in a grassy field.  

Hovercraft from UK manufacturers such as BBV Hovercraft and Vortex Engineering (and ourselves!) are likely to be ‘marine-ready’ is that is what most professionally manufactured hovercraft are built for. Look for stainless steel and alloy components to resist the dreaded salt water, decent buoyancy and flotation, freeboard and 4-stroke engines.

You may well come across an ‘unfinished project’ – either an unfinished refurbishment, or unfinished self-build hovercraft kit. Enthusiasm and cash often run out during the project and the resulting ebay sale can be a good buy if you have the knowledge and skills to finish it. But spotting what’s safe and effective in a hovercraft design is pretty tough if this is your first foray into the hobby. Before you go ahead, it may well be worth joining the HCGB - Hovercraft Club of Great Britain www.hovercraft.org.uk and asking for advice on the club’s Facebook page - the club forum is pretty much dead now, Facebook will get quick, helpful responses though. Take photos and find out as much as you can – it’s a small community and it’s quite  likely that somebody will even know the history of the craft.

Quite a number of older home built hovercraft will be powered by small 2-Stroke motorbike engines. These ‘Challenger’ hovercraft were often built from Hovercraft Club plans and have dated badly – they are little use for real-world cruising and unfortunately, they’ve also had their day as a competitive racing hull, so they’re little more than a casual play-around toy. 

The other type you may come across is a home-built hovercraft built from design plans. These can range from one to as many as six seats of 20ft or more. Provided the build quality is good (which can be very difficult to ascertain for a novice) these can be a pretty good buy and allow you access to proper cruising events and experiences. They’re competent enough as cruisers, but preparation for salt-water may be sub-standard. As mentioned above, inspecting the quality of the build and components is critical, as no two are the same.

Inspecting the hovercraft

Having found something that looks like it might do the job, go along for a look. Here’s our advice for some of the things you need to look for when inspecting a potential purchase.

Skirt
Just like the tyres on your car, hovercraft skirts are a disposable service item. A lot of hovercraft coming onto the market will feature a spectacularly well worn skirt. Material has shot up in price recently and a new skirt can be upwards of £500.00 so make sure you allow for it. If you see ragged edges or thin/de-laminating material – the segment needs replacement. Marlin (for example) skirts segments are around £9.00+VAT (or a whole skirt is approx £450.00) each so it’s  simple matter to count up the cost to get the skirt back into shape – most wear occurs on the front and read quarters. As long as you have a pattern (or even a sample) then a skirt can be made to sit any model – we’ve found ourselves with patterns for around 20 different models and can usually make replacements for other models. Avoid ‘cheap’ materials such as curtainside – it’s works badly and wears out quickly. Neoprene coasted Nylon is the right material.

 

An old ‘bag’ skirt will be patched and repaired, and be worn on the ground contact line. They can be very specialist to replace, requiring expensive material and glues, a lot of time and experience to replace – be ready for a substantial bill if a bag skirt needs replacement. In all honesty, unless it’s a big hovercraft (6 or more seats) a bag skirt is a liability. The better option for larger hovercraft is a ‘bag and finger’ (or ‘loop and segment’) skirt which combines a bag skirt which has segments below giving better performance and lower repair costs – the bag is not in contact with the surface and the segments can be more easily and cheaply replaced. 

Hull
Fibreglass (GRP,) other laminates, aluminium & wood are all good materials to build a hovercraft from. Plastic (such as HDPE) are best avoided. Through hard use, over the years, hulls will get knocked around in minor bumps, they’ll get scratched and dirty. That should all be visible, but look carefully at mounting points (fan frame/engine/steering etc) inspecting for cracks, distortions or damage repair. These are important mountings and need to be strong.

 

Make sure you look underneath the hull as that’s where it can take a real hammering, especially when badly driven over rocky terrain! Partly fill the plenum chamber with a garden hose and see if any water escapes – if it can get out, it can get in!

 Wood is tricky, there’s wood and wood. Marine ply is the best so you need to check the hull isn’t built from cheap material, and rotten. Look at the bottom, hovercraft often get put away wet which can cause wood to sit & rot.

Just remember that repairs add weight – hovercraft hate weight!  The good news is that GRP, wood and aluminium can be repaired fairly easily. Aside from the fact it’s too heavy to build a successful hovercraft from, another problem with plastic/HDPE is that it can’t be easily repaired.   

Engines
Engines in hovercraft can get a hard life – many poorly designed craft need lots of power lots of the time to operate - and car engines can be spinning constantly at 5-6000rpm. Given that these are often sourced from an old, scrapyard sourced donor vehicle that may have had another 20,000 miles in it, when fitted to a hovercraft, their life expectancy can be just a few hours. Flat 4 Subarus & BMW motorbike engines are both popular choices but getting pretty old now in 2017 and should really be rebuilt before fitting.

Small commercial engines (Kohler, Briggs & Stratton, Honda etc) are increasingly popular and designed to run at a higher load racing for a larger amount of their life. Aside from their economy and low noise levels, they’re light, simple, cheap to repair and service.

2-Strokes are a liability! Noisy, expensive to run and unreliable. They particularly loathe salt-water, but offer high power-to-weight ratio. They'll offend everyone within two miles with their noise however.

Whatever engine the hovercraft is fitted with, look for obvious signs of wear or neglect, noises, smoke and oil leaks. If you’re not confident on this, a friend knowledgeable in engines is very useful.

Fan / propeller & transmission
This inspection is critical. An old/damaged fan or propeller, badly mounted can be – literally – lethal. Walk away (or allow for replacement of) anything home made, or old fashioned ‘Truflow’ brand blades which are no longer available. Any sign of purple or green in a MultiWing or Hascon blade means it’s in need of replacement. Any cracks or significant chips in the blade means it needs to go - a new set can run to  £150.00-£200.00 or so, depending on the number. With propellers, check it’s a branded, microlight specification unit, and check for signs of erosion on the leading edge, caused by sand and grit in the air flow literally sand blasting the edge. Look for damage and cracks. Check the belt (cover may need removing) and check for fraying or tears but on balance I'd always replace an unknown belt - just like a cambelt on your car, they can fail without any prior visible wear or damage at high hours and quality varies enormously. Check for play and roughness in bearings and cracks in the fan/engine frame or mounting points where they bolt to the hull. Check that the fan guard(s) are complete and well fitted.

 

Controls
Steering and elevators (if fitted) are usually controlled by ‘bowden’ cables – they can corrode over time when used in a salty environment, so check they operate freely.

Performance : One of the challenges of hovercraft is that of performance. If it doesn’t work properly, it may be that it doesn’t work at all. It may not be able to operate over water due to skirt-drag or inadequate thrust, it may not hover properly because of poor fan or skirt design. Steering may be comprised due to poor rudder design. All this leads to the obvious conclusion that it’s very wise to try the hovercraft out before you part with any cash.

Our Advice in Summary

  • If you haven’t owned a hovercraft before, then buy a hovercraft in full, working order – NOT one that requires work or refurbishment.
  • Decide on the use for your hovercraft and research the model to ensure it is suitable.
  • Racing hovercraft are completely unsuitable for cruising and marine use.
  • Phone the manufacturer for advice and find out what spares are available.
  • Ask around, join the HCGB talk to experienced club members and operators.
  • Don’t buy a poor / unknown brand or design
  • Be doubly careful of the quality of components and construction of homebuilt hovercraft.
  • Double check safety, construction & guarding of rotating parts.
  • Budget for a full service, skirt wear and any obvious repairs.
  • Ask if it is possible to test the hovercraft.

 

Below - a good example of a hovercraft advertised on ebay which is well worth buying..... (or not!)

(Seriously, this was on ebay last year and he wanted money for it!)

 

 

Below - An awesome bit of kit, £10,000 gets you a missile capable of 0-60mph in under 5 seconds. BUT - not suitable for cruising or salt-water use.

 

 

 

 

An old-fashioned 'Skima' Hovercraft - ugly by today's standards and ancient design means it's very, very loud! (photo : James Hovercraft / Hovercraft Museum)

 

 

 

Buying a new hovercraft - Turn-key, Build or Assemble? What are the options?

added by russ on March 21, 2017 at 07:02

All three options have their advantages. Companies like ourselves and a number of others, supply a turnkey product to buyers who want to get out there and have fun using their hovercraft. Just like you’d buy a jetski, boat, car or quad, you spend your money and make your choice as to the brand, size and specification.  For your money, you get a fully warranted, reliable vehicle which should be certified and built to the standards of the MCA Hovercraft Code of Practice. It really should be that simple!

There’s basically two other options.

Build from plans

Companies such as Universal Hovercraft in the USA will sell you a set of plans and you can build the whole hovercraft yourself. You’ll buy the timber, source an engine or two, sew up your own skirt, source fan assembly parts, build steel fan frames, upholster seats and decide what colour gloss it needs to be finished in. It can be a fascinating project – as long as you have the necessary space, time and (crucially) skills & knowledge to complete it safely.

Unfortunately, where new and first time owners/builders are concerned, it’s probably fair to say that more don’t get finished than do. It’s a major project, demanding and time consuming. Enthusiasm and cash often run out before the projects completed – especially given the price of marine quality plywood nowadays! This often means that they end up on ebay as another unfinished project (which in themselves can a be a good buy if the work has been completed safely and well.)  

So, if it does make it to completion, what do you have? Well – taking the Sevtec & Universal designs, they’re very much a water craft designed for the American market – much more at home on big, open areas of water than exploring creeks and gullies. Their bag skirted design can be a challenge on mudflats and the large propeller means they can lack maneuverability. This means they work well as a long distance cruisers on calm water, but they’re not really a thrilling ride.  Think more ‘limo’ than ‘Lotus’ and you have the idea!

Without the development that a professional manufacturer puts into their craft, homebuilds should always be inspected by a competent engineer before operation. The terrible 2011 incident in New Zealand, when a man who’d built a hovercraft was killed by the propeller flying off the first time he used it just illustrates the point only too clearly.  But dramatic accidents aside, (this was an unfortunate but inevitable accident) making the hovercraft work properly can be nearly as big a job as constructing it. The builder often become despondent the first time out when it doesn’t work and it ends up - you guessed it - on ebay. Fine tuning the skirt, lift and thrust fans/props, matching the engine to the fan and selecting the correct speeds, getting the trim right, chasing away vibrations and making the steering safe…none of it is a five minute job and can soak up hundreds of hours of painstaking development.

And so, a year after work began, and with the homebuilder still setting-up his craft and ironing out problems, the feller who bought a professionally manufactured craft has many hours of hovercrafting adventures behind him. Now that’s not to say that the homebuilder isn’t enjoying himself – but it’s certainly a different type of enjoyment!

The other issue with regards building a hovercraft is the resale value. Being of (usually) a timber or aluminium construction, they usually look pretty crude,  and are often seen to sport features such as (I kid you not) plastic garden chairs for seating. It’s rare that a homebuilt hovercraft will fetch even a fraction of what it costs to build (especially if you price in your own time.) Sadly, it’s a fact that people simply aren’t prepared to pay much for your own efforts - rather like with homebuilt/converted camper vans. Some are very good, but they’ll never get the same price as a coach-built one.  On the other hand, a well maintained, three year old commercially built hovercraft can reasonably be expected to retain as much as 75% of its value.

 

 

Some hovercraft home-builds can be....rudimentary! (below) Limited to grassy field, it would be best not set out on a maritime adventure in this one!

 

Build a Hovercraft Kit

Going back a few years, we realised we were being asked time and again to supply complete kits, so we introduced them and have sold many since then. This is very much ‘halfway house’ between buying a completed hovercraft and building a hovercraft from plans. The kits we supply contain everything needed to build one of our Marlin or Snapper models. The fiberglass hull is fully assembled so that the fit-out is simply a mechanical project which is well within the capabilities of any competent mechanic without needing specialist tools and equipment.

Whilst it gives the builder the satisfaction of building their own machine, there’s two major advantages in the kit, compared to building a wooden hovercraft from a set of plans – aside from the fact it’s a much quicker build, meaning you can get out and play with it that much sooner!

Firstly, it’s going to work. Engine, fan, transmission, hull design are already decided and have been successfully used hundreds of times. No guessing, no calculations - follow the instructions and you’ll build and play!

Secondly, and this one’s a big one, it’ll be worth money when (if!) you come to sell it. The GRP hull’s are the same as we use on production, ‘turn-key’ hovercraft so that the finished article looks basically the same as those models. No clumsy wood, sharp corners, garden chair seating or unfinished edges – the finished hovercraft will look the part and fetch a good price.

 

 

 

 

Options for a ‘new’ hovercraft

Whether you buy a complete, turn-key hovercraft, a hovercraft kit, or build a hovercraft is down to your own skills, funds and wishes of course.  We're here to advise, just pick up the phone!

The next part of this series looks at the various aspects of hovercraft design, with advice about what to look for in a used / second-hand hovercraft.

 

 

 

 

 

Buying a new or second hand hovercraft? Some advice to avoid a costly mistake!

added by russ on March 20, 2017 at 05:39

Introduction

There's more used hovercraft than ever currently offered on Ebay, Gumtree and other sites - so now seems a good time to offer some advice to potential buyers. They're still, to most people, a bit magical and often misunderstood. That they are the most environmentally sound powered vessel available should be a massive boon to their popularity but – but this worthy fact is sadly often outweighed by unnecessarily noisy and unreliable examples which cause too much of a disturbance and get the good ones a bad name!

But here we are in 2017, and with more professional, high quality cruising/recreational craft operating than ever before, it's fair to say it's an activity that's flourishing. Over the course of the last five years we’ve really seen both the hobby and the market radically change. There’s more manufacturers producing good quality, affordable and safe hovercraft - some excellent plans available for home builders, and new engines which make practical small hovercraft with great performance and reliability. On top of that, last year, the MCA issued an industry led ‘Hovercraft Code of Practice’ which sets out standards for hovercraft construction and reassures buyers they're getting a legitimate bit of kit for their money.

Throughout this brief series, we’ll look at what hovercrafting is all about, where/what to buy or build and the options open to you, where to operate your craft and what the Hovercraft Club of Great Britain(HCGB) is all about.

First Off - Racing Hovercraft

I’ve raced hovercraft with a mixed bag of success and it’s fast, fun & loud. Racing craft are a completely different beast to recreational craft and designed for blasting round a grassy field – they’re extremely lightweight and overpowered (top Formula Ones are nearly 200bhp….!) making them a spectacular sport. They feature some sublime engineering but push the limits of what's possible to the maximum - so they tend to break down a lot and are usually two stroke powered. They’re very noisy, don’t float very well and are completely unsuitable as a cruising/recreational vehicle…but when you open the throttle on an F1 and you’re doing 100km/h four seconds later - well, suddenly all the disappointments make sense!

Take a look at www.hovercraft.org.uk for more details about when and where to see these machines in action.

Racing hovercraft are singularly unsuitable for recreational and cruising use for the reasons listed above, and this brings us neatly onto the first – and most important piece of advice we can give you when looking at buying a hovercraft….Not all small hovercraft are the same - make sure you buy the right type and design of hovercraft for your purposes!

We'll roll the information out over the next week or so, looking at different designs, suitability and 'what to look for' with regards parts and components when buying a hovercraft second hand. The important thing is that you understand right from the off that not all small hovercraft are the same - to avoid disappointment - and possible danger - we want to make sure you buy the right type and design of hovercraft for your purposes.

Recreational Hovercraft - What’s it all about?

Hovercraft come in all shapes and sizes from small single seat examples, medium size commercial/passenger vehicles to the massive American LCAC naval landing craft, which can deliver a squad of Marines and an Abrams main Battle tank to a contested beach . All work on the same basic principle of the vehicle riding on a cushion of air, generated by engine driven fans. This principle allows the hovercraft to travel over any sealed surface – grass, sand, ice and snow, water etc etc. Personal/Recreational/Cruising hovercraft (the three terms get used and are all pretty much the same thing!) are typically 1-6 seats and used as a leisure vehicle in much the same way as a Jetski, Boat or Quad etc. Some folks choose to build their own craft, others prefer to buy a professionally manufactured craft with the benefits of a warranty and proven design. In both cases, you have a vessel which allows you access to anywhere boat can go - in addition to its incredible shallow water/intertidal/amphibious ability. It’s this unique ability that make hovercraft so appealing to a growing number of enthusiasts.

There are plenty of events organised by clubs - especially in the United Kingdom, USA and Australia and suitable, well maintained hovercraft are just as capable of solo or ‘buddy’ cruising in protected waters as any other marine vehicle.

As a quick example of a recent cruise, four of us launched two-seat integrated, professionally manufactured hovercraft into the Swale in Kent (the stretch of water separating the Isle of Sheppey form the mainland.) From there, we traveled up to the River Medway - the Medway's a hovercrafter's heaven with massive tidal sandbanks and mudflats. In no time, we were exploring the gullies and saltings which no other vehicle can access. We visited a WWI German U-Boat laying at Stoke Marshes, climbed inside a Napoleonic Fortress and took a spin around 'Deadman's Island' (a macabre yet fascinating island containing the - often exposed - graves of quarantine victims and French Prisoners of War….) Then it was off to Upnor Castle for Sunday lunch and a pint, before returning via Bee Ness Jetty, Grain Tower and finally home via our favourite hover pub 'The Old House at Home' in Queenborough. In all we covered 65 miles, used less than three gallons of fuel and all agreed it was a fabulous day out. I'm still grinning as a I write this….

So where do you start?

First off, you’ll need to decide what you’re planning to use your hovercraft for. You might just want it as a toy for driving round a big garden/inland lake or playing field. You might be a bit more ambitious and planning maritime cruises. The usage does have a big effect on the type of craft you’re looking for. Larger 3-4 seat hovercraft are often more challenging to steer in confined places, but more comfortable on long distance cruises. Small hovercraft are great for inexperienced drivers and kids and are more sporting in nature – providing bigger thrills.

Are you a builder or a buyer? Lots of people over the years have built hovercraft as much for the thrill of building it themselves as for what it can do. Lots of them built one at school and are revisiting that. We’ll come onto building craft in due course, but for now it’s enough to consider whether you have the time, money, skills, tools and space to invest into what is going to be a huge project building a successful hovercraft.

If you're going to buy a craft, new or used? What are the pitfalls of buying a used hovercraft (or even a new one….) and how can you avoid them? More than ever, there’s a thriving recreational hovercraft scene in the UK.

There’s a massive range of hovercraft out there, some good, some bad, and some plain dangerous! Before we start getting into specifics in tomorrow's article, there's plenty of places for you to start your research, a few of which are listed below.

www.Youtube.com (type hovercraft cruising into search)

www.hovercraft.org.uk (the world's biggest club - 30 quid a year to join is money well spent!)

http://britishhovercraft.com/Contact.aspx (our own contact page lists up events companies where you can go along and drive a hovercraft.)

 

 

The 37Efi fuel injected Vanguard hovercraft engine from Briggs & Stratton

added by russ on March 1, 2017 at 09:10

 

 

In 2016, Briggs & Stratton released a new fuel injected version of the ‘big-block’ 35bhp engine that we use in our Marlin & Coastal-Pro hovercraft. Upgraded to 37bhp and with fuel injection, unfortunately, it was initially only available in the US market. We had to beg and plead with Basco (the UK importers) for some months before the US would give one up for us to test.

The motor has already proved popular with the ‘Mud Motor’ community so we had high hopes it would make a good hovercraft engine. When we did get our grubby mits on the first one in Europe, we ‘hoverised’ it and installed it into a Marlin ‘Beast,’ handing it straight over to no less than Jeremy Clarkson to open the ‘Clarkson, Hammond & May LIVE’ shows. When we got the craft back (reasonably undented, remarkably!) we got down to proper testing, putting another 50 or so hours on it with no issues whatsoever. Then we removed it and fitted it into a Coastal-Pro MACV where it has behaved impeccably for another 60 hours.

So what do we think?

Well, we love it to be honest!

Headline power figure is only 2bhp more than the regular, identical-but-carburettored V-Twin. However, it feels considerably stronger than that – and fan data seems to suggest that it could be nearer 40bhp than the advertised figure. Meanwhile, the improved torque of the engine is very apparent, with excellent throttle response and a higher resistance to ‘fan-stall’ when turning at high speed. Tickover is very smooth, and it appears to be slightly more economical, though that is more difficult to accurately quantify.

Since then, we’ve fitted eight to customer craft and they’ve performed really well.

Installed in the Marlin, it makes for a lively performer with excellent hump performance and injects some real sparkle into the craft. In a Coastal-Pro, the engine gives noticeably more push, which is great news when undertaking demanding work or with more load on board.

Price-wise, it’s a more expensive engine, so the premium is £450.00 compared to the standard 35bhp carburettor engine. Personally, I think it’s worth every penny – but it’ll depend on your own requirements and budget of course.

For more details, call or email us.  

 info@britishhovercraft.com

0044(0)1304 619820

 

 


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