
The highest of the three observation platforms, the Sky Deck, has only a wire mesh roof, so visitors are open to the elements. At the top is a triple observation deck, providing a 360° view of the city of Portsmouth, the Langstone and Portsmouth harbours, and a viewing distance of 37 kilometres (23 mi). The steelwork was fabricated by Butterley Engineering. The tower represents sails billowing in the wind, a design accomplished using two large, white, sweeping metal arcs, which give the tower its spinnaker sail design. It can be seen from the Isle of Wight, the Manhood Peninsula, Highdown Gardens and Cissbury Ring in Worthing and Nine Barrow Down in the Purbeck Hills, Dorset. The tower is visible around Portsmouth, changing the horizon of the area. The tower, at a height of 560 feet (170 m), is one of the tallest accessible structures in the United Kingdom outside London.

The tower was designed by local firm HGP Architects and engineering consultants Scott Wilson and built by Mowlem. It has three viewing platforms one on top of the other at heights of 100 m, 105 m and 110 m. The tower's design was chosen by Portsmouth residents from a selection of three different designs in a 1998 public poll.

It is the centrepiece of the redevelopment of Portsmouth Harbour, which was supported by a National Lottery grant. The Spinnaker Tower is a 170-metre (560 ft) landmark observation tower in Portsmouth, England. Spinnaker Tower at night in 2005 note the lipstick building had not yet been built
