the current light in the 23 metres (75 ft) north west tower is 37 metres (121 ft) above mean sea level and flashes five times every 30 seconds and with flashes 3.7 seconds apart. it can be seen for around 24 nautical miles (44 km) in clear weather. the east tower contains the foghorn, which produces two blasts every 60 seconds and this has a nominal range of 3 nautical miles (5.6 km). the south west tower is topped with a helipad and there is another helipad on a flat section of the rock. the rocks are also marked using racon with a morse letter t on radar displays. the lighthouse complex was automated in 1990 and is monitored and controlled from the trinity house operations control centre in harwich.