Why should I fit a Stealthdrive™ instead of a conventional electric outboard?

• Safety and Reliability: Previous attempts at motorising kayaks have often been profoundly unsafe, with the two greatest risks being either a prop strike upon the user, or losing the boat altogether, in the event of a capsize or man-overboard situation. Our design provides a unique combination of safety and fail-safe features, not available from any other product:
  
  
  • Capsize Detection:The Main Unit includes two motion sensors and specially-developed artificial-intelligence "G-Shock" logic that can discriminate between rough sea conditions and an actual capsize, combining rapid shutdown in a capsize situation with full immunity to false triggering. Once the craft is righted, a button must be pressed and held for a few seconds to re-activate the system, so unexpected re-starts are impossible too.
    
    
  • Man-Overboard Detection: A safety lanyard is provided, which is clipped to the user's clothing or buoyancy aid as desired. This operates a sensor which instantly cuts power if the lanyard is pulled by the user falling out. This, combined with the capsize detector, makes a prop strike upon the user impossible, provided it is used correctly.
    
    
  • Overload Detection: The Stealthdrive constantly monitors the motor current and shuts down in the event of an overload or short circuit. This electronic cutout is resettable with a button press, and does not result in a blown fuse which could leave you stranded -- that can be a major risk on competitor systems.
    
    
  • Fault Detection: The Stealthdrive is fully self-monitoring with dual microprocessors that cross-check each other many times every second, and will shut down in the event of any system fault. Thus there is no risk of going out-of-control due to a fault.
    
    
  • Highly Stable: The motor is placed low in the water, well below the centre of gravity, where it enhances the stability of the craft. Likewise, the battery is designed to be placed low in the hull for excellent stability.
    
    
  • Fully Sealed: The unequalled efficiency of the Stealthdrive's electronics allows the entire system to be watertight to the IP68 standard, and thus is unharmed by capsizing. Many competing systems cannot be fully sealed due to heat generation issues; Stealthdrive runs so cool that sealing is no problem.
    
    
  • Electromagnetically Compatible: The Stealthdrive is designed to meet or exceed all applicable CE (European Union) standards for Electromagnetic Compatibility (EMC), widely regarded as the most stringent in the world. The Stealthdrive has been carefully designed not to interfere with radio communications, GPS, sounders and other marine electronics.
    
    
  
  
• Efficiency: The Stealthdrive offers a unique combination of mechanical and electrical efficiency:
  
  
  • Mechanical: The Stealthdrive provides in-line, steerable drive just where you need it. Some competitor products position the motor over one side of the vessel, causing a grossly inefficient crabbing motion. Stealthdrive offers you unbeatable control and manoeuvrability.
    
    
  • Electrical: The Stealthdrive employs state-of-the-art PWM (pulsewidth modulated) motor drive circuitry and yields an industry-leading 99.5% electrical efficiency. This leads to cool running and best use of battery capacity, as well as permitting lighter-weight batteries to be used. The distance travellable on a given battery is far higher with Stealthdrive than with any competing system.
    
    
  
  
• Better By Design: To produce an electronics package of this high standard, Stealthdrive Ltd enlisted the services of a UK-based specialist electronics company with Ministry of Defence (MoD) approval and 30 years' experience in microprocessor-based control systems. The electronics is designed and built to the same quality as their aerospace/defence products and makes extensive use of military grade materials and techniques, to give you unequalled reliability, safety and performance. Toughness has been built-in to the electronics throughout; for example the system is unharmed by battery reversal, and can tolerate a momentary current surge (before the cutout trips) of a staggering 1,000 Amps. And the system's "memory" for settings, security codes and the like is designed to last at least a century, even without battery power!

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Choosing A Battery

• The run-time available from a given battery depends on a number of factors. Your use of speed and the capacity of the battery are the most important. Like any kind of engine, the harder you drive it the more ‘fuel’ is required.
  
  
• You can use any "deep cycle" lead-acid battery with the Stealthdrive, though we recommend a sealed, leakproof type (Gel or AGM type) for safety. We offer a range of specially selected AGM batteries at a very attractive price, that are ideal for the Stealthdrive, and we also offer a suitable charger (please note that AGM/Gel batteries must NOT be charged on an ordinary car battery charger -- a charger with a GEL setting is essential!) at a special price for Stealthdrive purchasers. Alternatively you may of course choose to obtain a battery and charger yourself.
  
  
• We offer a selection of different battery capacities to suit different users' needs, as shown below. We can also supply larger capacity batteries to special order when extended cruising times are required -- please contact us for details.
  
  Please be aware that at present, exchange rates and world lead prices are volatile, and for this reason battery prices are subject to frequent variation. Please contact our office for the latest pricing --- prices listed here are correct as of 1 August 2008 but are subject to change without notice.
  
  

  Battery Option	Amp-hours (Nominal)	Cruise Time (See below)	Weight(kg)	Price, inc.VAT
  A	28 Ah	5.5 hours	9.4	£45.00
  B	33 Ah	6.6 hours	10.9	£51.00
  C	44 Ah	8.8 hours	13.6	£61.00
  D	55 Ah	11.0 hours	17.5	£74.00
  E	70 Ah	14.0 hours	21.5	£111.00
  Gel/AGM Battery Charger (12 Amp, 12 Volt)				£32.00

  
  
  
• In the above table, the cruising time was determined using a Prowler 15 loaded with 125kg (a heavy load) and a cruising speed of 4km/h. As a guide to how battery discharge time varies with speed, at a 2km/h "crawl" the listed times can be multiplied by five, while running the motor flat-out runs the battery down in about one-quarter the listed time. Actual run times obtained are obviously dependent upon many different variables and these figures should only be regarded as a guide.
  
  
• With the motor stopped, the power drain of the Stealthdrive is negligible, making it possible to stay out more or less indefinitely.

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Will it fit my kayak?

• Currently the SD30 is designed to fit directly to the Ocean Kayak range of kayaks that have a rudder system installed. It will also readily fit to most other makes/types of kayak that are equipped with a rudder mount, please contact us for advice.
  
  
• For rudderless kayaks, which are popular in the UK, there are many third-party add-on rudder mechanisms available to which the Stealthdrive can be fitted, we are also in an advanced state of development with a "universal" steerable mount which should fit virtually any rudderless kayak and add the necessary mount and steering for the Stealthdrive. Please contact us for details.
  
  
• We will continue to develop appropriate mounts to allow fitment to other makes and models of kayak, there will be no surcharge for customers requiring a custom fabrication providing we can substantially retain our original design. Please contact us to discuss your specific requirements.

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I’d love to get on the water in a kayak but have a disability. Can Stealthdrive™ help?

• We are committed to making kayaking as inclusive as possible.
  
  
• We are willing to subsidise the manufacture of special controls to suit you, provided we feel that it is practicable and safe.
  
  
• The Technical Director of our electronics contractor is herself a wheelchair user with wide experience of adaptive control design and electronic aids for disabled people. Let us know your needs and we will do our best to help.
  
  

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How easy is it to install?

• Stealthdrive is designed for simple DIY installation.
  
  
• Full, illustrated instructions are supplied with the system.
  
  
• The system may either be permanently installed or made easily removable.
  
  
• You will require basic hand tools such as screwdrivers, spanners or wrench, and a drill.
  
  
• Permanent fitting should take less than an hour.
  
  

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What options are available?

For further details about any of these options, please download our User Manual.

A number of options are available to build on the basic system; you may choose to order options at time of system purchase, or add them as upgrades at a later date. All Stealthdrives™ have a basic cruise control function which allows you to "teach" the unit your desired cruising speed and then go straight to that speed with a single button.

• As standard, Stealthdrive™ is supplied for forward-only thrust. The Reverse option allows you to reverse the thrust, either to propel the kayak backwards or to allow fast deceleration. This can be useful for obstacle avoidance.
  
  
• Softlock™ is a valuable anti-theft and safety device which allows you to set a "pass code" without which the Stealthdrive™ will not operate; this works very much like the security numbers used on many car radios, and makes a stolen Stealthdrive™ useless to the thief. Softlock™ also prevents unauthorised or dangerous use, for example by young children.
  
  
• Pulsetrolling™ is a very powerful and unique automatic mode whereby you can "teach" the Stealthdrive™ a series of steps during each of which it runs at a chosen forward speed (which can include stop) for a chosen time (up to 4 minutes per step). It can produce an arbitrarily complex speed/time pattern with up to 64 steps in a program which will continuously repeat. It may be used for ‘hands off’ control for trolling or for other purposes such as guided tours. Once set, the program is retained until you decide to "teach" a new program, even without battery power.
  
  
• Hour Metering is an option which records the system power up and motor run times, allowing you to monitor usage of your Stealthdrive™. This is particularly useful in a boat-hire situation but other users may also like to keep a record for other purposes. Both counters are resettable by the owner. All Stealthdrives™ also incorporate overall, cumulative time metering, which may only be accessed by the factory. To accompany the Hour Metering option, especially in a boat-hire situation, we also offer an optional PC Interface which allows you to plug a PC into your Stealthdrive to read the hour meters and adjust settings more easily than doing this via the Handset. Details on request.
  
  
• Two further security features are fitted free-of-charge as standard to every Stealthdrive™, called Silicon Serial Number (SSN) and Owner ID (OID). Every Stealthdrive™ Handset and Main Unit possesses both an SSN and an OID. The SSN, as its name suggests, is a copy of the unit's Serial Number programmed directly into the silicon chips as an anti-theft device. All our Authorized Dealers record the SSNs of each Stealthdrive™ as it is sold, so the SSN can be used to spot a stolen unit even if the thief has altered the printed Serial Number on the unit. OID takes this idea one step further: each Handset and Main Unit can also store a text message of up to 58 characters, which is set to the customer's specification by the Dealer at sales time, and can be read back by any authorized Stealthdrive™ dealer. The OID is typically used to contain the owner's name and address, phone number, or similar. If you wish to have the OIDs of your system set, please simply inform your dealer when you order. This service is free-of-charge.
  
  

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What Maintenance is Required?

The required maintenance is minimal:

• After use, wash down your kayak including the motor assembly. This is especially important if used at sea.
  
  
• Ensure that the battery terminals and power connectors are kept clean and protected with a suitable anti-corrosion spray, or for preference a silicone-based protective grease.
  
  
• The cables, Main Unit and Handset should be cleaned with a damp cloth if they become contaminated. Do not use solvents of any sort, though a mild detergent may be used in cases of stubborn dirt.
  
  

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What Battery Care is Required?

• Always use the correct charger: a charger specifically suitable for Gel/AGM batteries must be used. This may be a dedicated Gel charger or a multi-purpose charger with a Gel-Mode switch, in which case Gel Mode must be selected. Using an unsuitable charger may damage the battery.
  
  
• Do not store the battery in a discharged condition. Always recharge it after use in order to maximise the battery's life.
  
  
• Protect the battery terminals with a moisture-repelling grease.
  
  
• Make sure battery contacts are clean: dirty contacts will cause a loss of power.
  
  
• If the Stealthdrive is to be laid up for a period exceeding one month, we recommend that you unplug the battery from the Main Unit.
  
  

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How Waterproof Is it?

The Main Unit, Handset, Handset connector and motor power cable connection are all fully waterproofed and suitable for use at sea, protected to International Standard IP68. In addition the Handset is designed to float.

The system is built of top-quality materials throughout, to ensure full sea-water resistance. All electronics is double-hermetically-sealed in corrosion-proof polymer materials, the rudder-blade/motor-mount is entirely made in 316-grade Stainless Steel, a full 3mm thick, for tremendous strength and total corrosion-proofing. Contrast this with the more common practice of using mild steel coated with plastic -- much less strong, and the first scratch will let corrosion run riot.

The Stealthdrive system is also unique in that it does not need a heatsink (cooling fins) -- always a point of vulnerability on systems which have them. The unbeaten efficiency of the Stealthdrive electronics means that no heat removal is required; even at flat-out the system gets barely tepid to the touch. Any system that does require a heatsink is by that very fact less efficient than the Stealthdrive, no matter what its makers might claim -- any heat that requires removal equals wasted energy.

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How Much Does It Weigh?

• Motor, Prop, Rudder Blade and Cable: 4.6 kg.
• Main Unit and Cables: 0.5 kg.
• Hand Control: less than 0.1 kg.
• Battery: Depends on size chosen; see Battery List above for weights of each.
• Don't forget that your existing rudder blade is no longer required, saving some weight.

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Does Stealthdrive™ Manufacture Other Systems?

• We can supply higher output systems to order, up to four times the output power of the standard SD-30, for use in larger vessels than kayaks. The SD-46 is a 12-Volt system with twice the output power of the SD-30, while the SD-70 is a 24-Volt version with four times. The larger systems can either be used with single, large motors, or with two (SD-46) or four (SD-70) of the standard SD-30 motors.
  
  
• We also have a number of other products in development which include an outboard-motor-compatible, cavitation-plate-mounted version for slow trolling, and a bow thruster for large trailer boats and small launches.
  
  
• Our control circuits also have applications in automation and process control.
  
  
• Please contact us to discuss your requirements!
  
  

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I've Thought of Another Option I would like!

If you think of an option that we don’t currently offer, and we consider it feasible to add to our offerings, you can have it for free!

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I Have Another Question!

Time to contact us at enquiries@stealthdrive.co.uk

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