Tayvallich has a very small tidal range, approximately 1 m at Springs and 0.5m at Neaps.
The height of the tide is heavily influenced by wind. Prolonged Southerly winds push all the tide levels up above normal, whilst prolonged Northerly winds push it down.
There are double High and Low waters, conforming roughly to the following pattern in relation to Oban.
The second High Water may be fractionally higher than the first High water and the Second Low Water may be fractionally lower than the first Low Water.
The main ebb and main flood take only 3 hours each.
1st H.W. - 3hrs 30mins before H.W. Oban
2nd H.W. - 30 mins before H.W. Oban
1st L.W. - 2hrs. 30 mins after H.W. Oban
2nd L.W. - 5hrs 30 mins after H.W. Oban
Spring Tides occur when H.W. Oban is at approximately 0645 GMT (0745 BST)
Neap Tides occur when H.W. Oban is at approximately 0045 GMT (0145 BST)
Oib Rock (On the East side of the entrance to Caol Scotnish)
There is a rocky shoal patch about 20m SSW of the Oib Rock mark with a least depth of 0.6m.
Keel boats should therefore keep 30m South of the mark.