Britain's hardest-hitting motorboat magazine

Significant powerboating innovations seem to have a lot in common with buses. You wait for ages for something to come along, then out of the blue a convoy of Routemasters roll up at once.

Take propulsion systems. The idea of an engine turning a long shaft with a propeller stuck on the end has been around since shortly after Noah took to the high seas, and remains the number one choice of most big boat manufacturers today. But that might be about to change, if a number of new ideas currently under development live up to their promise.

In the same month that Volvo Penta take the wraps of their much heralded Inboard Propulsion System (featured in January issue), two smaller British companies also claim to be on the verge of major drivetrain breakthroughs. Suffolk-based Duodrive are completing trials of a counter-rotating propeller system for shaftdrive applications (featured in January issue) and Pursuit Dynamics of Hertfordshire are hard at work developing their radical steam jet propulsion system into a credible alternative to the combustion engine (see MBM Sep 04 p5). But while all three of them are busy preparing obituaries for the single-screw shaft, I can't help feeling their proclamations may prove a little premature.

Creating a clever new propulsion system with a raft of theoretical benefits is one thing; convincing the wary old boat club commodore to chop in his trusty Perkins shaftdrive for a steam-powered jet or forward-facing prop is quite another. I'd love to be proved wrong, but when it comes to boating, the mantra 'practice makes perfect' always seems to win over 'vorsprung durch technik'.

Hugo Andreae, 16 December 2004