Alderney to The Isles of Scilly

We left Braye Harbour at 9am on Wednesday 27 July.  It meant that we experienced a messy tidal flow as we headed west and a bit north to clear Burhou, the Casquets and all the off-lying rocks but Nicky had worked the plan so that we would start to get the benefit of the westward tidal flow as we crossed the shipping lanes which we had to cross heading north.  There was no wind to speak of, but we had calculated that that we needed to motor most of the way towards Land’s End or risk getting trapped in the English Channel when the winds started to build briskly from the west in a couple of days’ time.

Leaving Braye Harbour

All went well until 1325hrs when we had crossed the eastward shipping laneand turned back onto our westerly heading towards Lands End.  The engine revs dropped briefly and then recovered; both of us heard it and knew immediately that something was not right.  Ten minutes later the engine revs dropped off again but recovered when we pulled the throttle back.  Our assessment was that the fuel supply to the engines was being restricted by partially blocked filters.  The worst case was that this was due to diesel bug contamination which would mean a complete clean out of the fuel system.  We’d need a decent sized boatyard to get that work done; Plymouth or Falmouth were the most likely locations to find that sort of help but they were a good distance away.  Dartmouth was a possibility, and it was closest.  So, at 1350hrs we turned to head towards Dartmouth running at reduced speed with 1700rpm set. That seemed to be low enough revs to keep the engine running smoothly. 

There was still no wind to speak of and we had another shipping lane to cross.  We really needed to know a bit more about what was wrong with the fuel supply.  Perhaps the disturbed seas as we had left Alderney had shaken the fuel up enough for some contamination at the bottom of the tank to be sucked up into the filters.  A bad case of diesel bug contamination however could potentially block the filters and pipes completely.  Clearly, we didn’t want that to happen and end up drifting in the middle of a busy shipping lane.

Our engine fuel supply line has a special device to catch any diesel bug debris before it gets to the first filter.  If we had a bad case of diesel bug that unit would be full of the contamination; we knew it had been empty and clean a couple of weeks previously when we had carried out an engine service, though we hadn’t had time to change the fuel filters then.  So, when we were right in the middle between the 2 shipping lanes, beside the Channel Light buoy, we shut down the engine and started drifting whilst we checked.  Removing the diesel bug catcher, checking it, reassembling and bleeding any air out took about 10 minutes. We were very relieved to find the diesel bug catcher was completely clean.  So, we hoped that the problem was just a build-up of debris in the normal fuel filters; they were due a change.  However, changing those would take much longer and potentially would allow lots of air into the fuel supply which can take some time to clear.  We didn’t feel that there was enough space between the shipping lanes to change the fuel filters if there were any complications.

Instead we continued on with reduced revs to cross the second shipping lane and then on towards Dartmouth. Eventually, we felt that we had enough sea room to drift whilst we worked on changing the fuel filters. Changing them went very smoothly and we got the filters changed and the fuel system clear of air in just 20 minutes.  The engine ran smoothly again at full power – problem solved! 

Much relived we set our course towards the Lizard, just east of Land’s End, and continued west on a glassy sea.

At nightfall we switched onto a 3-hour watch system with one of us asleep below whilst the other worked the boat.

Not a great picture but it does show a bit of the blue phosphorescence in our wake

Throughout the night we were regularly visited by dolphins and we also experienced some really bright blue phosphorescence.  The edge of our wake was picked out really distinctly in blue and when the dolphins swam past it looked like we were being overtaken by bright blue ghosts.

Looking back at Land’s End and the busy shipping lane we had had to cross

Land’s End is another busy shipping area with a traffic separation scheme.  Once we were past the Lizard, Nicky, who was on watch, had to time crossing behind a series of ships approaching Land’s End.  Our direct route to the Isles of Scilly would clip the traffic separation area so on my watch there were some more ‘wiggles’ to dodge ships and a short leg off our direct course to cross part of the shipping lane heading at 90 degrees to the line of the TSS.

Entering Crow Sound

Thereafter it was an easy sail into Crow Sound, just northeast east of St Mary’s, the largest of the Isles of Scilly.  We wanted to move on to other anchorages but the tide was too low for that, so instead we anchored in Crow Sound at 1340hrs aiming to move on in a few hours.  Whilst we waited, Nicky checked in with Customs and Immigration to let them know that we were back in the British Isles.  Meanwhile I looked at MarineTraffic to see if we recognised any yachts in the Isles of Scilly but instead discovered that out track had stopped a few miles northwest of Alderney.  We had been picking up ships all the way here but they would not have been able to see a signal from us; not great when we had been crossing busy shipping lanes.  Running the diagnostics showed that the dedicated GPS aerial for the AIS had failed.  A bit of wiggling and tightening and it came back online; looks like we had a loose connection at the GPS aerial.

View towards St Martin from our position at anchor in Crow Sound

Crow Sound, Isles of Scilly