Tidal Streams

[Guest]

I have a question that has been puzling me. I am a scuba diver and dive along the Dorset coast. When planing for a dive it is essential to have slack water or know the rate.When I look at the Admiratly Charts for the Potrland area the rates refer to H/W Plymouth.When I cross check this with the Tidal streams they refer to H/W Portland.There is a considerable varience in the H/W times. For example 17/4/01 there is 23 min difference 25/4/01 there is 64 minuets.Is there a difference table I know there both std ports ? I have asked this question with divers and had no responce .Many thanks for any help Paul.

 

[Guest]

Forget Local HW . . .

You will find that in the Poole - Portland Bill area Slack Water, when the tide actually turns, co-insides (give or take half an hour, depending where you are) with HW Dover and HW Dover+6.

Also note that:

From LW Dover to HW Dover current flows from West to East and from HW Dover to LW Dover East to West.

On Springs HW Dover is at midday

On Neaps LW Dover is at midday

 

[Guest]

Re: Tidal Streams - and within minutes

and six hours difference, it is exactly the opposite at Falmouth.

That's what makes tide tables with HW Dover easy(ish) for use at Falmouth - HW Dover is LW Falmouth, and LW Dover is HW Falmouth.

regards, Philip

 

[Guest]

There is a detailed tidal stream atlas for the approachwes to Portland, originally devised for the benefit of submarines exercising in the area. It is based on HW Devonport.

My copy was published by the hydrographer and was on sale to the public for two shillings and sixpence, but I expect it costs more than that nowadays.

The formal title is:

Approaches to Portland, Pocket tidal stream atlas.

It covers from 02 38 W to 02 12W

 

[Guest]

Paul

If you go to your local chandlers you will be able to get a very useful booklet on local tidal streams in that area - much more detail than a normal tidal atlas. The times of slck water will vary with local seabed geomorphology and if you are planning a drift there are numerous counter currents.

Can't remember the name of the author as the booklet is on the boat. I think the cover is blue?

 

[Guest]

Thank you all for the replys you have all been most helpful.

Paul