William Bourne (mathematician)

He described how to make observations of the sun and stars, using a cross-staff, and how to plot coastal features from the ship by taking bearings using triangulation.

He designed an enclosed craft capable of submerging by decreasing the overall volume (rather than flooding chambers as in modern submarines), and being rowed underwater.

The 21st device listed is the earliest known description of a ship's log and line, which he attributes to Humprey Cole, an officer of the Tower Mint.

[1] The 75th device on the list is a description of a night signal or early semaphore system to be used between people on distant ships who had previously decided on a code consisting of a series of lights and fashion of standing.

The device was said to have been employed by mathematician and surveyor Leonard Digges and Bourne was asked to investigate it by Queen Elizabeth I's chief advisor Lord Burghley.

Submarine by William Bourne, in Inventions or devices , 1578.
The first page of "Inventions or Devises" by William Bourne, published in 1578