Adolphus Knell is believed to be one of the sons of 19th century marine painter William Adolphus Knell (1818-1875). There were at least four well known sea painters in the Knell family, including John Henry and William Callcott Knell. At different times members shared the same residential London address, but their exact relationship to one another remains somewhat unclear. However, their individual artistic styles are easily identified.

Adolphus Knell was first listed as a painter in bath and later moved to Bristol, England, where he continued to live and paint for most of his career. A number of excellent and attractive marine paintings bearing his signature have survived and today are considered quite collectable. His style progressed with time to a more widely flowing brush stroke than the other members of the family used.

Working on various support materials within a wide array of size, Knell's marine subjects are most often the busy harbors and waterways of Southern England. Known scenes by the artist include Thames estuaries and ports along the Bristol and English channels, especially in the Solent and the Isle of Wight. With this in mind, it makes sense that a large collection of images of his work is in the old customs house, Lymington.