RCD – Recreational Craft Directive (EU 2006)

RCD was originally a set of safety and design criteria to regulate the construction and design of 2.5m to 24m leisure craft in Europe. Ratified in 1998, the boat building industry has been working to the directive since then. During 2003, an updated version, EU 2006 was ratified to include noise and exhaust emissions, ready for 2006 onwards.

2006 target levels of Environmental Emissions were added to bring together safe and responsible design with environmental measures. This now ‘All-encompassing’ leisure boat directive regulates boats marketed and sold throughout Europe - replacing the previous targets for exhaust emissions, set through world recognised institutions and legislation like EPA - USA’s Environmental Protection Agency, CARB - California Air Resources Board and Bodensee Shipping regulations.

The exhaust requirements take the form of limits of acceptable emissions of carbon monoxide, hydrocarbons, nitrogen oxide and, in the case of diesel engines, particulates. The noise emission requirements are presented in terms of maximum acceptable sound pressure levels determined by a ‘pass-by’ test.

Exhaust emission levels are similar to the most stringent previously agreed worldwide and target engine manufacturers to reduce pollutant gas or particulates below agreed limits by a certain time. However, there are 3 different target levels, one for 4-stroke petrol and one for diesel/compression engines, both implemented 1 January 2006 and another for 2-stroke petrol to be implemented from 1 January 2007. This is because the 3 different technologies require differing development changes to achieve the targets. In essence 4-stroke is the most stringent because they’re already quite low.

The target limit for 4-stroke is the lowest and the earliest to reach the final goal limit set for 2006 – that means, regardless of any decals, declarations or testaments by any manufacturer, 4-stroke technology will REMAIN the cleanest solution to boat power for the foreseeable future and beyond the current RCD EU2006 or 2008 directive.

All Honda outboards are 4-stroke and are defined as being in the ‘Ultra-low 3 star’ emissions category, the lowest possible level in the industry.

Noise emission levels are set by the whole craft package, so the same engine in different boats will produce different noise levels as it passes by depending on exhaust type, mounting, damping and exposure. It has been accepted that the latent pass-by noise of a boat moving through water with no mechanical propulsion system at all, is an acceptable noise within the boating environment, so it is the powering of a craft at a given speed that is the key factor.

For boats powered by outboards, the directive has defined that the noise level to be concerned with is purely that of the noise of the engine mounted on the transom. So, the manufacturer of the outboard is tasked to achieve the standard rather than the manufacturer of the boat. If the engine meets the noise target of RCD EU2006, then it is defined that the boat package does too. Again, as for exhaust, there are 3 levels of targets, one for diesel/compression engines, one for 4-stoke petrol, both implemented 1 January 2006 and another for 2-stroke petrol to be implemented from 1 January 2007.

The noise target limit for 4-stroke is the lowest and the earliest to reach the final goal limit set for 2006 – that means, regardless of any decals, declarations or testaments by any manufacturer, 4-stroke technology will REMAIN the quietest solution to boat power for the foreseeable future, beyond the current RCD EU2006 or 2008 directive.

That is why at Honda we have taken the decision to highlight the difference in RCD targets for 4-stroke and 2-stroke by having a decal denoting "4-stroke RCD" rather than simply RCD.