Something of a polymath, Rand appears to have had at least three successive careers. During his early adulthood his energies were devoted to running the school in Lewes that had been initially founded and operated by his grandfather, Cater Rand 1684 - 1748. The syllabus under Cater Rand jr. seems to have been strongly biased in favor of new (or newly rediscovered) subjects such mathematics and certain technical sciences.
In 1779 Rand established himself as a book seller and in 1784 he was declared bankrupt. It seems that he had borrowed twice on the same security without informing his (potentially) competing lenders. The bankruptcy was still undischarged in 1806. These were difficult times, and the southern coast of England would have found itself on the front line in the event that the much feared invasion of England by the imperial forces of Napoleon Buonaparte had materialised. Along the way, in 1799, Rand found time to patent a design for military and naval telescope intended to improve and facilitate range-setting for heavy guns on the battlefield.
From 1790 Rand was giving his occupation as surveyor. The topography of the area around Lewes ensured ample challenges as well as providing practical advantages for a local man with extensive local knowledge. By the end of his career he was apparently acknowledged widely as the local expert in his field. Early on he was involved in at least one railway project. At this time railways were, of course, not yet operated by moving steam engines, but it may be that already Rand and his contemporaries were contemplating these as a future possibility. Rand was also involved in mineral engineering at a time when lignite deposits had recently been discovered locally. Cater Rand's later projects were more preoccupied by the hydrographical challenges involved in managing the estuarial area, in order both to improve access for shipping and to address the problems caused by flooding which then, as subsequently, was a feature of the Lewes area in the event of heavy rain combining with high tides.