The D-class (RFD PB16) lifeboat was the first of a class of inflatable boat operated between 1963 and 2007 by the Royal National Lifeboat Institution of the United Kingdom and Ireland. It was replaced operationally by the .
They were manufactured by R.F.D. Co.Ltd of Godalming, Surrey, a company founded by engineer Reginald Foster Dagnall. Over time, RFD became a synonym for "Rapid Flotation Devices".
Increasing numbers of leisure craft in waters around Britain and Ireland in the late 1950s caused the RNLI to consider using inflatable boats as Inshore Lifeboats (ILBs). A boat was purchased for trials and the work of the lifesaving society in Brittany was studied. This resulted in RFD PB16 inflatables being modified and fitted out as ILBs.
The first was deployed at in 1963. It capsized on its first launch but was soon put to good use. Once in service, the main problems came from the boats deflating and from the outboard motors failing. It was decided that these should be replaced every year.
Production continued until 1984, however two alternative designs were tried in 1971 and 1972. Only a few Avon S650 were built but the Zodiac III proved more successful and series production of these started in 1975 and continued until 1987. The last PB16 was withdrawn in 2002.
The PB16 was long and fitted with a single 40 outboard motor.