The D-class (IB1) lifeboats are inflatable boats serving in the Royal National Lifeboat Institution (RNLI) inshore lifeboat (ILB) fleet as well as a number of Independent Lifeboats around the UK and Ireland. Although they are known as the "IB1" at times, they are the latest development of the D-class lifeboat and as such are mainly referred to as a "D-class".

This class of lifeboat is one of the smallest operated by the RNLI, and they are a common sight at lifeboat stations round the coast. Unlike other members of the ILB fleet, the D-class (IB1) does not have a rigid hull. All others with the exception of the Arancia-class lifeboats, hovercraft and all-weather lifeboat tenders are rigid inflatable boats.

The IB1 normally has a crew of three or four and is primarily used for surfer/swimmer incidents as well as assisting in cliff incidents where the casualty is near the water. The very nature of its work requires a swift response, and the IB1 can normally be afloat very quickly.

As of February 2020 the minimum crew for an RNLI IB1 was raised from two to three. Some Independent Lifeboats have different crewing levels to the RNLI.

All of the following fleet details are referenced to the 2026 Lifeboat Enthusiast Society Handbook, with information retrieved directly from RNLI records.

RNLI D-class fleet D-600 – D-699 Op. No. Name Station CommentsMetcap 2001–2002 TrialsFirst 2002–2007 Training fleet (D-600C) 2007–2015 Flood RescueD-601Jenny Topham 2002–2003 Trials 2003–2011 Relief fleet 2011– Training fleet (D-601C)D-602Gilbert Goble 2002–2004 Trials 2004–2013 Relief fleetD-603Forever Forward Denise 2002–2004 Trials boat 2004–2011 Relief fleet 2011– Training fleet (D-603C)D-604Marie Turner 2002–2004 Trials 2004–2013 Relief fleetD-605Joan and Ted Wiseman 50 2003–2011 First operational IB1 2011–2021 Training fleet (D-605C) D-606 Jennie B 2003–2012 D-607 Spirit of Berkhamsted 2003–2017 D-608Helen and Ian Tytler 2003–2011 2011–2023 Training fleet (D-608C)D-609248 Squadron RAF 2003–2011 2011–2022 Training fleet (D-609C)D-610Catterick 2004–2012 Relief fleet 2012– Training fleet (D-610C)D-611The Young Watsons 2003–2011 2011–2012 Relief fleet 2012– Training fleet (D-611C) D-612 Dave and Trevor Jones 2003–2012 D-613 Jack Cleare 2003–2012 D-614 Flo and Dick Smith 2004–2012 D-615CSMA/Frizzells 80th Anniversary 2004–2012 Relief fleet 2012– Training fleet (D-615C) D-616 Amy Lea 2004–2012 D-617 Henry Philip 2004–2012 D-618 Blue Peter VI 2004–2012 D-619 Blue Peter III 2004–2013 D-620Edna May 2004–2012 Relief fleet 2012–2024 Training fleet (D-620C) D-621 Duncan Ferguson 2004–2013 D-622May II 2004–2013 2013–2014 Relief fleetD-623Peterborough Beer Festival II 2004–2013 2013–2014 Relief fleetD-624Spirit of the RLC 2004–2013 2013–2014 Relief fleetD-625John Charles Raybould 2004–2012 Relief fleet 2012–2022 Training fleet (D-625C) D-626 David Leslie Wilson 2004–2014 D-627 Arthur Bate II 2004–2014 D-628 Austin Burnett 2004–2014 D-629 The Shannock 2004–2014 D-630Langley Muir 2004–2012 Relief fleet 2012–2016 Training fleet (D-630C)D-631Spirit of Juniper 2004–2014 2014–2018 Inshore Lifeboat Centre D-632 Godfrey and Desmond Nall 2004–2014 D-633 Pride of London Foresters 2005–2014 D-634Rusper 2005–2014 2014–2018 Relief fleetD-635Semper Paratus 2005–2012 Relief fleet 2012–2023 Training fleet (D-635C) D-636 Valerie Wilson 2005–2014 D-637 Aldergrove II 2005–2014 D-638Richard John Talbot Miller 2005–2014 2014–2018 (SAR BB-638) D-639 Howard and Mary Broadfield 2005–2015 D-640Mabel Davies 2005–2016 Relief fleet 2016– Training fleet (D-640C) D-641 Blue Peter IV 2005–2015 D-642 Amanda, James and Ben 2005–2015 D-643Tra Mhor 2005–2015 2015–2018 Boarding Boat D-644 Philip Booth 2005–2015 D-645The Martin Jolly 2004–2012 Relief fleet 2012–2015 Training fleet (D-645C) 2015–2018 Inshore Lifeboat Centre D-646 Hannabella Ferguson 2005–2015 D-647 Barry Lazell 2005–2015 D-648 Spirit of Mortimer 2005–2015 D-649 2005–2015 D-650Helen Olive Palmer 2005–2015 Relief fleet 2015–2016 Training fleet (D-650C) 2016–2019 (SAR BB) D-651 John William Hirst 2005–2015 D-652 Team Effort 2005–2015 D-653 William Hadley 2005–2015 D-654Angel of Holyhead(Civil Service No.46) 2005–2016 2017–2024 D-655Guardian Angel(Civil Service No.47) 2005–2015 Relief fleet 2015– Training fleet (D-655C)D-656William Robert Sanderson 2005–2016 2016 Relief fleet D-657 Sally 2006–2016 D-658 Sir Y Flint 2006–2016 D-659 George Godfrey Benbow 2006–2016 D-660City of Leeds II 2006–2012 Relief fleet 2012–2017 Training fleet (D-660C) 2019 (SAR BB)D-661Jane Anne III 2006–2016 2017–2023 Boarding Boat (BB-661) D-662 Eleanor 2006–2016 D-663 Duggie Rodbard 2006–2016 D-664 Puffin 2006–2016 D-665The Doris 2007–2016 Relief fleet 2016–2022 Training fleet (D-665C) D-666 Number not used D-667 The Rotary Centenary Queen 2006–2016 D-668 Colin Bramley Parker 2007–2016 D-669George Bearman 2006–2017 2017– Boarding Boat (BB-669) D-670 Harold Arnold 2007–2017 Relief fleetD-671Sheringham Shanty Men 2007–2017 2017– Relief fleet D-672 Ernest and Rose Chapman II 2007–2017 D-673Christine 2007–2017 2017–2024 Boarding Boat (BB-673)D-674OEM Stone III 2007–2017 2017–2024 Boarding Boat (BB-674)}}D-675The Doris and Harry B 2007–2017 Relief fleet 2017–2022 Boarding Boat (BB-675)D-676Leslie and Peter Downes 2007–2017 2017–2023 Boarding Boat (BB-676) D-677 Jacky Hunsley 2007–2014 D-678Rotarian Clive Tanner 2007–2017 2017–2022 Relief fleetD-679Gráinne Uaile 2007–2017 2018– Boarding Boat (BB-679)D-680Marjorie Wilkinson 2007–2017 Relief fleet 2017–2024 Training fleetD-681Olive Herbert Two 2007–2017 2018– Boarding Boat (BB-681)D-682The Essex Freemason 2007–2017 2018 Relief fleet 2018– Boarding Boat (BB-682)D-683Tradewinds 2007–2018 2018– Boarding Boat (BB-683) D-684 Telford Shopping Centre 2007–2018 D-685Winifred 2007–2012 Relief fleet 2012–2018 Training fleet (D-685C) 2018–2023 Boarding Boat (BB-685) D-686 Peter Downes 2008–2018 D-687The Western 2008–2018 2018–2023 Boarding Boat (BB-687) D-688 Albert Wordley 2008–2018 D-689Enfys 2008–2018 2018– Boarding Boat (BB-689)D-690David Young 2008–2013 Relief fleet 2013–2015 2015–2019 Relief fleet 2019– Boarding Boat (BB-690) D-691 Betty and Thomas Moore 2008–2018 D-692 Connie Dains 2008–2018 2021 privately owned D-693 Mark Noble 2008–2018 D-694James Bissett Simpson 2008–2018 2019–2025 Boarding Boat (BB-694)D-695The Pat 2008–2019 Relief fleet 2019– Boarding Boat (BB-695)D-696Anna Stock 2008–2019 2019– Boarding Boat (BB-696)D-697Stranraer Saviour(Civil Service No.49) 2008–2018 2019– Boarding Boat (BB-697) D-698 The Sheila Barrie 2008–2019 D-699 Daphne May 2008–2019

D-700 – D-799