Abstract: The present invention provides an apparatus adapted to survey a predetermined characteristic within a body of fluid adjacent an axis that transects the body of fluid, the apparatus comprising: a survey member interposed between first and second position defining arrangements; and at least one instrumentality associated with the survey member, each instrumentality adapted to survey the predetermined characteristic of the body of fluid adjacent the axis, wherein a survey of the predetermined characteristic is conducted over a predetermined time period. The present invention provides a method of surveying a predetermined characteristic within a body of fluid adjacent an axis that transects the body of fluid, the method comprising the steps of: deploying into a body of fluid at least one apparatus according to the first aspect of the invention; and obtaining survey data of the predetermined characteristic from one or more of the instrumentalities over the predetermined time period.