Position : Latitude 53 11′.18 N Longitude 4 12.5’W
Satellite Derived Position 0’01S. 0’08E
Lock Basin Light: F.WR Vis R225-357 W 357-225

Approach to Port Dinorwic

From the North: The Britannia Bridge lies 2 nm to the north of Port Dinorwic. To the south east of the bridge, on the opposite shore to Nelsons Statue is an Historic Wreck. Avoid this by keeping north of the channel until the Straits turn south. The Lock opens up to port 300m after the start of the residential development and below the Hotel Port Dinorwic.

From the South: Provided due care is taken the passage between Caernarfon and Port Dinorwic is danger free. The lock entrance opens up to starboard 300 mtrs before the end of the residential developments.

Sailing From Port Dinorwic

Bound North from Port Dinorwic:
The correct time to pass through the ‘Swellies’ is at HW or LW slack. This is -2 Hours Liverpool (-0052PD). However, due to the height and time between the ends of the Straits, passage north at this time means you effectively travel up hill, against the tide. By timing your arrival at Britannia Bridge ( 2nm from PD) – 3 hours before Liverpool (-0152PD)you will gain a favourable tide to Bangor, then a period of relative ‘slack’ until you gain a ‘new ebb’ toward Puffin Island and the northerly exit of the Straits

Bound South from Port Dinorwic:
The tide flows with considerable strength along the full length of this end of the Straits. Provided due care is taken, however, the passage is danger free between Port Dinorwic & Caernarfon. ( Note buoyage change near Caernarfon). It is best to leave Port Dinorwic early as you will need to push against the last of the flood. The aim is to reach Fort Belan at the southern entrance (to the Straits (5.5.nm) at the top of the tide (-0025PD) This will allow passage over the Bar at maximum depth. Passage over the Bar at half tide is not recommended even in calm conditions.