An excellent drift dive for experienced divers. The dive starts from the seaward side at a depth of about 7m. You should aim to enter the channel on the flood tide, and aim to be swept into Loch Etive (use your judgement about current strength, or take local advice, as this varies considerably with the state of the tide).
You will get pulled through under the Connel Suspension bridge before being taken by the current down to a maximum depth of 30m.
Strong eddy currents are reported at 30m, and you may have to swim strongly to escape these before you can make your ascent as the current slackens as the loch widens out.
Boat cover is recommended.
The falls are generated when the water level in the Firth of Lorn (i.e. the open sea) drops below the level of the water in Loch Etive as the tide goes out. As the seawater in Loch Etive pours out through the narrow mouth of the loch, it passes over a rocky shelf which causes the rapids to form. As the tide rises again there is a period of slack water when the levels are the same on either side. However due to the narrow entrance to the Loch, the tide rises more quickly than the water can flow into the Loch. Thus there is still considerable turbulence at high tide caused by flow into the Loch. Thus, unlike most situations where slack water is at high and low tides, in the case of the Falls of Lora slack water occurs when the levels on either side are the same, not when the tidal change is at its least. As a result the tidal range is much greater on the coast than it is inside the loch.
Entering Loch Etive from the south bank next to Skerries Bridge, swim out into the flow and then descend to about seven metres. Keep working your way into the tide or you can easily end up in an eddy that will simply deposit you at the side of the loch. You will see various bits of debris on the seabed from the building of Skerries Bridge. This is where your speed picks up – don’t be surprised if you experience an easy six to eight knots.
Suddenly, there is a drop off where divers really begin to pick up speed. Currents will pull divers down to about 30m (despite the figure on the Admiralty chart, which states only 20m). Watch out for the eddies at the base of the wall, which are caused by the uneven seabed. They can hold you there, so swim hard away from the wall and you’ll pick up the main current again.
As the water becomes shallower, the current will slow, as this is where the loch widens. You will surface downstream from where you started, this is generally where the boat will pick you up. The dive itself lasts only about ten minutes, but it’s definitely worth it.
The best time to dive the Falls is when they’re in flood, as the visibility is better. At ebb tide, the visibility can be poor and you need to start deep and ascend quickly, which isn’t ideal. Slack tide is classed as an HW (high water) Oban, although it does differ from the figures given. The best idea is to get there early and watch the tide change yourself, then start the dive when you feel comfortable with the conditions.
At certain times, particularly during spring tides, you need to be prepared for the possibility of separation from your buddy. If this does happen, you may not be able to surface immediately to find him or her, so stay calm and wait until you can ascend safely without overexerting yourself.
While this dive can be done as a shore dive, boat cover is strongly recommended.