
This section contains details for Regular Branch Diving, i.e. one day events
along the Sussex Coast. Details of procedures for more distant sites, and for
expeditions, will be published in due course.
Regular Branch Diving
All the resources that you require are
the Dive Marshal’s kit, either in paper form, or online. We have attempted to place as much of the Dive
Marshal’s Kit as possible onto the Branch Web Site, so you should be able to
undertake most, if not all of the steps below, even if someone else has the
physical kit at the time.
Because of space requirements, much of the Dive Marshal resources are kept on
the Members-only web site. This causes one or two technical problems, which we
will get around by opening links to these resources in another window. As long
as you leave that window open, you won't have to keep logging-on!
1 - Pre-planning
All you need to plan at this stage is a date that you want
to go diving, and somewhere to dive.
You may wish to consult the Diving Officer on your ideas of
what may be an interesting dive and ask for support when needed to cover diver
training or dives involving wreck surveys etc.
You probably already have a date in mind, but if not, then
you may wish to choose one that has a low tidal range in order to minimise
currents. Look at the
Tidal Range Plot for the year (at the start
of the Tides section in the DM Kit) and select a day than has a low tidal range
if possible.
You also need to decide on a dive site, and a launch site
that is near to it. When selecting your launch site then consider
- car parking facilities
- launching point for the boat
- local bye-laws or council orders
- harbour master’s rules
- toilets and preferably refreshments
- distance from home base
- alternative interests for families if attending.
Please also consider where the Club is planning on diving
within the two weeks before and after your dive (look at the
Diving Calendar on this site). It is nice to have a varied
diving schedule, and avoid going to the same places time after time.
2 As early as possible
Having set a date for your dive, and decided on a potential
dive site and location ….
2.1
Advertise
Your dive needs to be properly advertised, and members made
aware of what, where, when, how much, etc.
If you are arranging the dive at short notice, there may not
be time for the above, so instead you should send an email to shortnotice@crabbsac.org.uk,
and tell everyone about your dive.
2.2
Start Planning
As you work out the details of your plan, write them down on
the
Dive Planning Sheet.
Start the sheet by writing in the date and location of the day.
Pick a suitable and accessible launch site / harbour for your
chosen dive site
There may be a choice open to
you, especially if the site is about the same distance from two or more
harbours.
Write in the harbour that you will be using.
Obtain the Lat/Long for the harbour entrance (your cox will want to know where
to come back to!). Details for common launching sites along the Sussex/Kent
coast can be found at
http://www.bsac-se.org.uk/Launching.asp
. While you are there, you can write in the Mean Spring Range and Mean Neap Range
at the same time.
Work out the tides for the day.
Refer to the
Shoreham Tide Tables contained
in the DM Kit (and the
Notes
that go with them) or an Almanac, and obtain the relevant details for the day. Remember
to add the one hour in the summer months. Copy them onto your plan.
There are also links to EasyTide
from the Regional Web Site, but be warned that this only works for up to seven
days ahead. See
http://www.bsac-se.org.uk/Tides.asp
Do a few calculations.
These will come in useful later.
Calculate the Tidal Range by subtracting the height of the low water from the
height of the adjacent high water on either side of the time you want to dive.
While you are there, calculate
the Range Percent using the following formula. This may come in useful later if
you want to calculate slacks precisely. If you don’t do this step then that’s
ok.
Range % =
(Tidal Range)-(Mean Neap Range) / (Mean Spring Range)-(Mean Neap Range)
This will give you an idea of how
strong the currents are going to be – 100% represents mean spring currents, and
0% represents mean neap currents.
Work out the slacks for the day, and write them in.
You can use the rough figures for
slack contained (sometimes) on the right of the
Shoreham Tide Tables in the DM Kit.
Alternately, you can find the
nearest Tidal Diamond to your dive site (write the chart number and diamond
letter onto your worksheet), and use the
Tidal Diamond Plots in the DM Kit to
work out the slack more accurately. Please see the following web page for
further details on how these are worked out:
http://www.bsac-se.org.uk/Slacks.asp
Remember that the diamonds
probably refer to a different port to the one that you will be using, so you
may have to calculate the tides for that port as well at this point. Enter
these details into the “Ref Port” section of your planning sheet.
If you feel that you need to work
out precise slacks for the day, then you will need to use the following two
spreadsheets. Save them onto your computer, rather than accessing them directly
from the website. The second one contains full instructions how to do this.
Assess the available windows for launching and diving
Many harbours may dry out to the
point where you cannot launch or retrieve your boat. Newhaven needs at least
2.0m over Chart Datum, while others, such as Littlehampton have a bar at the
river entrance which “dries” to about 1 metre above Chart Datum, and represents
a dangerous obstacle around low water, again requiring at least 2.0m over Chart
Datum. Shoreham has a lock system which only opens at certain times.
If you are affected by either of
these, then carefully calculate when you can launch / leave the harbour, and
make a contingency plan in case you return late and cannot get your boat out!
Obtain GPS co-ordinates for the dive sites.
Some of the more popular wreck
sites on the South Coast are listed on the Wreck page of the Regional Web Site
at
http://www.bsac-se.org.uk/Wrecks.asp
.
Other sources will include Dive Sussex,
but beware that most of the co-ordinates in that book (and other similar ones)
are in OSGB36 format, and in Degrees, Minutes and Seconds. If you need to
convert these, use the calculator at
http://www.bsac-se.org.uk/OSGB36.asp
The more sets of co-ordinates
that you can get for a particular wreck the better. It is much easier for the
cox'n to find a
wreck within an area than to precisely hit a point which might be at one end.
Work out an achievable timetable for the day
This may be possibly the hardest
task to do, as you’ve got to second guess how efficient your divers are going
to be on the day.
It is best to work back from the
middle, and to do this, you need to know
- when your period of slack water is going to be,
- how long it is realistically going to last,
- whether you are diving in one wave or two
Here are two examples, assuming
that our slack water is at 13:00, and out divers will be diving for a total of
30 minutes.
Example 1: One wave.
| 12:15 |
15 mins |
Arrive at site, locate wreck, drop shot |
| 12:30 |
15 mins |
Divers kit up |
| 12:45 |
30 mins |
Divers in water |
| 13:00 |
|
Slack – middle of dive |
| 13:15 |
15 mins |
Divers surface, start de-kitting |
| 13:30 |
10 mins |
Retrieve shot |
| 13:40 |
|
Leave site |
Example 2: Two waves.
| 11:50 |
15 mins |
Arrive at site, locate wreck, drop shot |
| 12:05 |
15 mins |
Wave 1 kit up |
| 12:20 |
30 mins |
Wave 1 in water |
| 12:50 |
10 mins |
Wave 1 surface, start de-kitting |
| 13:00 |
10 mins |
Slack – middle of dive |
| |
|
Wave 2 kit up |
| 13:10 |
30 mins |
Wave 2 in water |
| 13:40 |
15 mins |
Wave 2 surface, start de-kitting |
| 13:55 |
10 mins |
Retrieve shot |
| 14:05 |
|
Leave site |
By starting in the middle like
this, you can now work backwards and forwards through the day.
Allow sensible amounts of time,
an hour to prepare the boat at the start and end of the day, and remember that
a lot of time will be spend motoring at slow speed in the harbour before you
get out into open water.
You should now have a good
outline plan of your day, and a sensible set of timings, so write it all down on
the
Timetable Planning Sheet.
Plan the second dive
It takes very little more time
and effort to give your divers a second dive, (usually some sort of drift dive
in our waters), so create a plan that will make this happen.
You may also get circumstances where some more junior divers cannot take part
in your main dive, and you must provide a good opportunity for them to get wet
during the day.
On occasions this may not be possible due to launch and recovery windows, but
careful planning can help. Do not think that a “second dive” must happen after
the “first one”. If you have a mid-afternoon slack, then organise the “second
dive” for the morning, putting in your inexperienced divers with their
instructors. Obviously the latter will not be able to dive in the afternoon,
but may be happy to cox the boat for you. Make it happen!
Prepare your backup plan.
A backup plan is needed in case
things happen, or go wrong, and your original plan cannot be successfully or
safely executed. There should be no need to abandon a days diving just because
you hadn’t prepared a backup plan. The sorts of things that you specifically
need to plan for are:
- You can’t find the wreck you were looking for –
Have reliable, trusted,
and tested coordinates for a backup wreck, not too far away from your original
site.
- The weather is too rough for your dive site –
Have coordinates for a
backup, more sheltered dive site.
- The weather is too rough to go to sea from your harbour –
Plan to take
your diving party to an inland dive site instead.
3 - In the week before
Listen to the weather forecasts each day and watch the weather.
As your dive draws closer, you can start to get more and more accurate weather
forecasts. See the links to weather resources on the Regional website at
http://www.bsac-se.org.uk/Links.asp
Collect details of members of your dive party from the original
notice or however.
Complete the
Dive Planning Sheet – Personnel with the names.
Refer to the pages in the DM Kit to determine their grades, and to
find out towers, cox’ns, and rescue skills. Make notes about all these on your
Personnel Planning Sheet. You may find it helpful later to fill out the form
with the most experienced people at the top, and the least experienced at the
bottom.
Review the plan in light of the people and the places involved.
Can everyone participate in the dive, or are there some who are too
inexperienced for the dive you have planned. If so, then you may need to have
them dive only on the second dive of the day.
Allow for any training requirements you may be asked to include,
but don’t necessarily wait for them to come to you and ask. If you have some
inexperienced divers, then it is highly likely that you can arrange some
relevant training for them during the day. Make it happen!
Decide pairings based on experience levels and interests. There
is plenty of BSAC guidance about pairing divers, especially if you are faced
with “techies” using Nitrox, Mixed Gases, or Rebreathers.
In the absence of any other criteria, it is safe to pair the most experienced
with the least experienced, and work through your list that way until you reach
the middle. Try to avoid threesomes wherever possible, but if they prove to be
required, make sure that they consist of two more experienced divers and one
less experienced diver, rather than the other way round.
Organise the divers
Make sure everyone knows where to meet, and when. Arrange maps for everyone
if necessary.
Organise the boat preparation
Ensure all equipment is present and correct.
Select members of your dive party to tow the boats.
Tell them if
they have to fill the boat(s) with fuel on their way to the launch site. Ensure
that there is enough two-stroke oil available for what you have planned for the
day.
Decide who coxes the boats and who goes in which boat.
Complete
the Dive Waves Planning Form with these details
Check everyone is properly equipped and will have enough
cylinders and air for the day.
Prepare marshalling slates, pencils and erasers for each boat
Prepare a formal Voyage Plan.
Complete a
Voyage Planning Sheet for each boat that you plan to be used, and for each
trip out that it is going to make. Make sure that you include details such as
any dangers, and harbour speed limits and signals.
Review your plan in light of the above.
Is it still achievable?
Is it within the experience and capability of all the divers who will be
attending? Is it within the range and capability of the boats given the number
of people attending (with eight divers and their kit, the Tornado is capable of
about 20 nautical miles on a full tank if driven sensibly). Re-plan your day if
necessary.
4 - On the day before
Get an accurate tidal plot for the next day
Get one for both your
harbour and the reference port for your tidal diamonds. See
http://www.bsac-se.org.uk/Tides.asp
Get the
Shipping Forecast
and Inshore Waters
Forecast for the day ahead.
Decide whether the dive goes ahead or whether you have to revert to your
backup plan. Makes sure that all your divers know what will be happening (get
them to telephone you between 18:00 and 19:00 on the day before the dive).
5 - On the day
5.1
At the start of the day
- Get there first
- Verify that the boats are topped up with fuel and oil
- Give a thorough briefing to your diving party, but don’t tell
them more than they need to know. A blow by blow account of the day’s timetable
will just bore everybody. Tell them:
- necessary details about the site, including facilities
- when they must be kitted and ready by
- who they will be diving with, and when
- which boat they will be in, and who the cox’n is
- how much the day is going to cost, and when you will be
collecting it.
- when you expect to be back on shore
- how long any breaks, eg for lunch, will be
- when you expect the day to finish.
- Appoint Deputy Marshals to supervise boat preparation and
launching. Select a member of your party to be responsible for the Dive Records
for the day.
- Separately, brief cox'ns on passage plan, dangers, and harbour
speed limits and signals. Provide them with the marshalling slates, pencils and
erasers for each boat. Have them sign the Voyage Planning Sheet for their boat.
- Arrange for payment of launch fees
5.2
During the day
- Keep an eye on the weather and sea conditions.
- Ensure someone on shore has details of your plans, including
return time, and instructions about what to do if you do not return within a
reasonable time.
5.3
At the end of the day
- Ensure that the person on shore who has details of your plans knows
that you are back.
- Check everybody is accounted for, and give a debriefing to your
party
- Collect payments from divers.
- Ensure nothing is left on site, and be last to leave.
5.4
Back at the Club Hut
- Clean the boat.
- Report any defective or broken equipment.
6 - As soon after the dive as possible
Just in case
Although we all hope that it will never happen, the Incident
Report Form appears below if needed.
This should be completed as fully as possible. Please actively involve
the Diving Officer in the completion of this form, as it is his/her
responsibility to forward it on to BSAC HQ.
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