Needles to Start Point

[Greg34targa]

Morning,

I am after some advice for a trip from the needles to Start point (Salcombe bound).
I have a targa 34 and will be doing the voyage with a friend who will be in a rib with 300hp engine.

We would like to set off early, however that would mean rounding Portland Bill in an unfavourable tide. It is our intention to go in a straight line from the Needles to Start Point so we will be at least 5 or possibly 10 miles out.

Not including the wind would we need to still be conscious of the tide?

Thank you

Greg

 

[Homer J]

Usual advice is stay 7 miles out, tide shouldn't be too bad if you have 300bhp or go in close ( a tennis ball hit away from shore) but not against the tide as it will be rough.

 

[tross]

90Nm (ish) in a rib! are you sure? I hope he has an inboard otherwise he is going to need a refueling stop ( I think)

 

[LadyInBed]

The effect of an adverse current is proportional to your cruising speed. If you cruise at around 18 knots then a 5 knot current against you for an hour isn't too much of an issue, but it would be a pain at 7 or 8 knots.
Ps should that be inversely proportional?

 

[Tranona]

If you are going at planing speed (around 20 knots) the passage will take around 5 hours - less than one tide, so it makes sense to go with the west going tide as you will get between 10-15 miles from the tide which reduces the passage by around half an hour. However if there is a westerly wind (common) you may find the head seas worse and definitely need to keep offshore near Portland.

Your planning needs to take into account all the factors that affect your boat when choosing the day and times.

 

[alant]

Morning,

I am after some advice for a trip from the needles to Start point (Salcombe bound).
I have a targa 34 and will be doing the voyage with a friend who will be in a rib with 300hp engine.

We would like to set off early, however that would mean rounding Portland Bill in an unfavourable tide. It is our intention to go in a straight line from the Needles to Start Point so we will be at least 5 or possibly 10 miles out.

Not including the wind would we need to still be conscious of the tide?

Thank you

Greg

Only if you have bumpy wind over tide conditions against you.

 

[James_Calvert]

No expert on fast power boats but I would definitely check what the tide is doing during your intended passage.

Possible issues would be needing to slow down due to wind over tide effects resulting in much slower progress than planned. The faster the tidal stream the greater the effect.

But generally its in the vicinity of headlands that the tide is strongest so I don't think you'd need to do more than work out what it will be doing in the Needles Channel, off St Albans Head, Portland Bill of course, and Start Point. And think about how moving your departure time forward or back could affect sea conditions in these places and also how a slower than planned passage might work out.

 

[guernseyman]

The effect of an adverse current is proportional to your cruising speed. If you cruise at around 18 knots then a 5 knot current against you for an hour isn't too much of an issue, but it would be a pain at 7 or 8 knots.
Ps should that be inversely proportional?

Neither.

It's algebraic addition.

 

[Greg34targa]

Thank you for all your advice - much appreciated!

 

[Malabar]

With your boat wind against tide = bumpy; wind with tide = happy.