The Shakewell seacock, is a plastic thru-hull valve. Seacocks are the most critical component in a boat; their reliability can mean the difference between life and death. The importance of seacocks is not diminished by less dramatic circumstances: engines, toilets and cockpit drains can all be rendered useless by malfunctioning valves. The weekend sailor is as dependant upon them as the round-the-world racing skipper.
- To be easily, rapidly and safely cleared afloat, if blocked or jammed.
- To be capable of being serviced afloat, by taking all the moving parts into the boat, without tools, whilst still retaining useable water flow through the valve.
- To tolerate marine growth, shellfish and sand, but remain airtight even if the mechanism and valve canal become scratched by such particles.
- To shut flush with the hull to minimise turbulence and to hinder marine growth and mud entering and accumulating in the valve canal.
- To be non-metallic in order to eliminate all problems associated with corrosion, and to allow fitting to steel and aluminium, without risk of galvanic degradation.