Here are some notes for those wishing to ‘Round the Bill’ for the first time via the inshore passage.
The inshore passage is the navigable water between the rocks at the end of the Bill and the race. A distance of about a tenth of a mile.That may not sound much, but to put it in perspective, it’s probably more than the width of many harbour entrances. The race is not ‘parked’ in one place of course, it moves around depending on tidal conditions.
The seas around the Bill can vary between two extremes, sometimes in the same week. Calm and placid one day, with bass boats bobbing about right in the middle of where the ‘Race’ should be. Or, a few days later a seething mass of white water quite capable of buckling the plating on a frigate. The former occurs on the fine days, with neap tides and light winds in the same direction. The latter, when severe gales are trying to turn back the enormous energy of surging spring tides.
Why is it so wild? Well, you can see from the chart that just a little southwest of the Bill the depth goes from 78 m (say 250 ft) to 3 m (10ft) in less than a mile. That’s an awful lot of seawater to push up hill! Add to that converging tidal streams flowing from east and west of the island, and -.well, sometimes perhaps the safest place to see it all is from the lighthouse!
Glancing through the pages of the Tidal streams Atlas (NP 257) will quickly show when to go round the Bill, and when it is best to return. It can be seen that a stream of 7 knots occurs for one particular hour, bearing in mind that these numbers are based on the mean (average) springs and neaps. They can be, and are, higher (and correspondingly lower) at times.
But don’t be put off! Go west about 4 hrs after local HW, return east about 2 hrs before local HW, and the less range there is at the time, generally the easier it will be.
I would suggest that anyone unfamiliar with Portland Bill, and maybe not too experienced, take some, or all of the following steps.
Buy the Admiralty Portland chart number 2255 and the Tidal Stream Atlas NP 257.
Read the Pilot book instructions.
Choose neap tides and fair weather
Do the trip with someone who knows it.
Visit the Bill by car.
Pop up to the nearby National Coastwatch lookout station.
Pot buoys, sometimes sub-surface because they are dragged under by the current, are probably more of a hazard than almost anything else is out there. So keep a good lookout, and if you feel happier with your engine running, don’t have the prop turning unless it is necessary.
Happy sailing, Clive Sammels