In his book, “Experimental research on the physical conditions of life in the waters”, 1891, Paul Regnard (1850-1927), a French physiologist and medical photographer describes an instrument he named photometrographe to measure the penetration of light in the water, which was first tested offshore the island of Madeira in 1889 by the prince Albert I of Monaco in one of his oceanographic expeditions to the island. Regnard used platinographic paper because it had better sensitivity then the most commonly used silver chloride paper. On board was an equal device, exposed to direct sunlight, to serve as a control. In the end it was possible to compare the intensity of light during the various hours of exposure and determine the depth at which total obscurity was obtained. It was also in Madeira in the same year, that Prince Albert used for the first time a horizontal plankton net invented by him. During his oceanographic campaigns, Prince Albert, one of the most important oceanographers of the second half of the 19th century-early 20th century, collected many biological species in the sea of the islands of Madeira and Açores using photography as illustration in several reports of his expeditions. Collecting devices were tested in the campaigns such as the bacteriologic collector from Portier and Richard used for the first time at the Açores in the Princesse Alice II campaign, 1902. Other explorers as in the expedition Challenger did also some dredging and sounding at the Madeira and Açores islands, collecting in its explorations, deep-sea sea fishes and other biological species, represented in their reports by drawings and watercolours. In this paper it will be discussed how photography and other illustration techniques were used in the scientific reports of those early oceanographic expeditions to the sea offshore the islands of Madeira and Açores .