London Bridge Rock - Tobago Scuba Diving Site
Diving the St. Giles area is always weather dependent, so you won't know until you leave Man of War Bay if you will be able to dive these offshore rocks. Not until you arrive at London Bridge will you know whether the waves, surge and current will allow you to dive through the bridge. If there is even the slightest swell, the funnelling effect of the rocks leading to the hole accentuates its effect, making the passage through the hole unsafe.
From the surface, London Bridge is easily identified; the largest of a group of rocks to the north of St. Giles has a hole right through the middle like a polo mint. Half of the hole is above the surface and the bottom half is submerged. The waves delight in crashing through the hole then rushing back as if they fear what lies on the other side. There is a natural arch that extends down to 15 meters underwater. You will probably find schools of Tarpons in the 1-3 meter range.
The boat driver, manoeuvres the boat carefully in the entrance to the hole. So close are the rocks, executing a backward roll seems likely to risk a bang on the head. Of course, you should be positioned safely and drop into the water to begin your descent to the entrance of the hole. From the northern side, the entrance is wide; the bottom is at 35 feet and about 15 feet across.
The base of the hole is made up of huge slabs of rock like a magnified cobbled street. As you begin to swim through and the hole narrows, feel the thrust and tug of the water movement. The fish sway back and forth, suspended in space. Tangs, ocean surgeonfish, French angelfish, trunkfish and trumpetfish occupy the channel. The vertical walls are encrusted with yellow and orange sponges and probably a whole lot more.
Toward the end of the passage, it narrows to around 3 feet. The vertical sides tower above. At the end of the hole there is a lip and the instructions given in your dive briefing should be clear: swim over and immediately down to get out of the surge and current. Tip over the edge and find yourself at 45 feet, in an area of sand punctuated with big blocks like giant chess pieces. You'll soon be dwarfed by the terrain.
There is a flat area leading to a ridge that rises to 35 feet. The ridge is covered in vase sponges and a mass of fish and, thinking the excitement is over, begin to examine the marine life. But, over the ridge swim a short way before the mild current begins to carry you along a vertical wall, buzzing with life. Exquisite crinoids extend their long arms from vase sponges; green, yellow and amber varieties occur here. Dive the wall at 70 feet but it may seem equally lavish deeper and shallower. Deepwater sea fans are prolific at this depth as is wire coral and many hydroids. You will find tiny slate pencil urchins if you look carefully, 1 to 2 inches long, looking like sputniks.
Green finger sponges, dark volcanic sponges, yellow tube sponges and giant vase sponges oblige many angelfish with a constant supply of food. Rock beauties, French and grey angelfish and a splendid pair of Queen angelfish go about their business without any concern for us. Because the area is not over-dived, the fish are not particularly shy and simply ignore divers.
Just as with all Caribbean reefs, there is an abundance of parrotfish. Midnight parrotfish are not a common sight on most reefs, but you'll see many on this site. These big fish are midnight blue with lighter bright markings on the head above the mouth. Stoplight and princess parrotfish are also common around London Bridge. Smaller reef fish, such as bi-colour damselfish and chromis, create soft clouds across the hard rocky surface.
The current will carry you around a corner, look up at the rugged structures above you. Angular rocks shoulder away the waves as they rush at the cliff face. The wall looks like a series of giant steps; another impression that this terrain is meant for creatures larger than humans.
Swim around the western arm of the bridge and now pass across the entrance of the hole. A large rock ahead has attracted a big school of boga. They swim in a polarised school, their silvery blue bodies forming a streak of sparkling light, an underwater fireworks display. A few black jacks are hanging out near the entrance and you should find a spotted moray protruding from its hole, mouth agape as if pulsating in time with the surge.
Over the rock, another wall awaits our inspection. Spend the remainder of the dive slowly drifting along the wall at 30 feet. Swim away from the wall slightly to make your ascent, to give the boat room to manoeuvre. But, as soon as you begin to go up, the current may whisk you away. So, simply hang in it while you do your safety stop.
London Bridge combines an exciting and unusual submarine terrain with colourful interesting marine life. If the weather is right, it is definitely a dive to do!
Spectacular Rock Formation!
...the base of the hole is made up of huge slabs of rock like a magnified cobbled street. As you begin to swim through and the hole narrows, feel the thrust and tug of the water movement..
London Bridge Rock - At a Glance:
- Location: Caribbean NW Point
- Depth: 35-55ft / 11- 18m
- Dive time: 50 mins
- Time to site: 10 mins
- Skill Level: Intermediate to Advanced
- Drift: 0-4 kts