Buying a second hand hovercraft – some advice.

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)