NOVELTY - An electricity generating apparatus has a first shaft (10) for linear axial motion, a second shaft (12) for rotational motion; and a rack (21) and pinion (22) engaging both shafts so that the linear motion of the first shaft drives rotational motion of the second shaft. The pinion is mounted on a ratchet wheel and driven by the rack during linear displacement of the first shaft in upward direction. The first shaft is connected to an ocean surface and sub-surface buoyant body (136). The buoyant body causes the first shaft to linearly displace in response to ocean wave motions.    USE - Electricity generating apparatus for producing electricity using ocean wave energy.    ADVANTAGE - The apparatus provides wave motion detection adaptive to tidal levels, maintaining constant rotational speed for driving generator or performing other useful work. The apparatus can be fully automated in its operation, and utilizes water momentum to give rise to lateral forces for driving pumps. The generator and associated mechanical and electrical structures can be automatically adjusted to maintain effectiveness of the system.    DETAILED DESCRIPTION - An electricity generating apparatus has a first shaft (10) for linear axial motion, a second shaft (12) for rotational motion; and a rack (21) and pinion (22) engaging both shafts so that the linear motion of the first shaft drives rotational motion of the second shaft. The pinion is mounted on a ratchet wheel and driven by the rack during linear displacement of the first shaft in upward direction. A third shaft (13) engaged with the second shaft through meshing bevel gears (26,34) is coaxially connected to a flywheel or inertia plate (40) engaged with a generator (30). The first shaft is connected to an ocean surface and sub-surface buoyant body (136). The buoyant body causes the first shaft to linearly displace in response to ocean wave motions.    DESCRIPTION OF DRAWING(S) - The drawing shows the schematic view of an electricity generating apparatus disposed in an ocean.    First shaft (10)    Second shaft (12)    Third shaft (13)    Rack (21)    Pinion (22)    Bevel gears (26,34)    Generator (30)    Inertia plate (40)    Ocean surface and sub-surface buoyant body (136)