A Navigational Interlude

I’ve got a chance to catch up with blog writing today, the weather is inclement and gusting to 27 knots.  Gusting to 27 knots isn’t really a big deal but coupled with rain means a stay in port day for us and to be honest we’d planned 2 days in Tarbert anyhow.

Haven’t caught up with blogs for Day 2 and 3 which I’ll do in a bit but this blog is about navigation and specifically Buoys (that’s Buoys not Boys).  Where we’re parked in Tarbert Marina we’re about as close as you’ll get to one of the most important nagivational aids to a Mariner – A Cardinal Buoy.

Now the entrance to Tarbert Habour looks harmless enough at high tide but at low tide all manner of rocks and shallows are exposed.  So the need for navigational aids in the light and especially the dark are very necessary. 

Cardinals mark the extremity of a hazard (rocks, shallows, sandbanks etc), in this case it’s an West Cardinal which means danger to the East of it.  It’s identified by several means – the yellow and black banding, the black tringles on it’s top and a specific light sequence at night.  Here it is at low water, all the rocks behind it aren’t visible at high tide.

All good when it’s light but navigation buoys in the dark are a very different thing.  They all have different sequences, flashing slowly, quickly, short, long, in a sequence, say twice every three seconds.  There’s even something called ‘occulting’ where the light is on all the time and ‘flashes’ dark periods.  They also flash different colours – red, green, white or yellow, hence being colour blind makes you pretty much completely blind at sea.   The sequence and type is marked on the chart and enables the mariner to know what the buoy is (port, starboard, cardinal etc).   A West Cardinal flashes in a fairly helpful way – 9 times then a gap.  as you can see from the video below.

Now imagine trying to spot a light sequence in the Solent against a backdrop of street lights, car lights and random brightly lit shipping.  Not so easy.  Now imagine if the light sequence is one flash every ten seconds!  Sailing at night needs proper planning and is not for the feint hearted.

But boy are these buoys just fantastic at any time of day. 

Day 2 and 3 soon,

Vaughan