The Solent-class lifeboat is a steel-hulled version of the Oakley-class self-righting lifeboat and is sometimes referred to as the 48-foot, 6-inch Oakley-class Mark III. Solent Operational Numbers followed on from the first three 48-foot, 6-inch Oakleys and were interrupted by the last two Oakleys (48-12) and (48-13). The operational numbers of the Solent-class had three digits in the suffix to indicate a metal hull (as with Clyde, Waveney, Thames and Tyne classes, one Arun class and the first eleven Merseys). Two digits indicates a wooden, glass-reinforced plastic or fiber-reinforced composite hull.
The Solent was powered by twin 110 bhp Gardner 6LX diesel engines which gave the boat a top speed of . There were twin spade rudders installed which were coupled to Mathway manual steering gear.
Apart from the steel hull, the Solent-class differed from the Oakley-class in its self-righting mechanism. The Oakley used a water ballast system, while the Solent class was inherently self-righting as a result of its watertight superstructure. The Solent was the last class of traditional displacement-type lifeboats designed by the Royal National Lifeboat Institution.
There were two versions of the Solent, unofficially known as "Mark I" and "Mark II". The "Mark I" boats have a vertical steering wheel. Sliding doors provide access to the forward end of the wheelhouse on each side. The "Mark II" boats have a seated steering position with hinged wheelhouse doors at the after end of the wheelhouse. These boats entered service in 1972.
The first four Solent-class boats (ON 1007 â ON 1010) and the last three (ON 1019 - ON 1021) were built by Groves & Guttridge at Cowes. The second four (ON 1011 â ON 1014) were built by Camper & Nicholson at Gosport.