Bad Things You Need To Know About Falling Into The Sea

 In December we published a blog article about Man Overboard drills. This article describes some of the consequences of a Man Overboard from a medical viewpoint.  Keep in mind that the day it was posted here, BrambleMet showed a water temperature of 9^oC… only slightly warmer that the inside of most fridges. Ed.

Written by NCI Watchkeeper Dr Chris Aps FRCA

UK waters are cold.  Around Portsmouth the coldest sea temperatures are seen in February and March and are between 7 and 9 degrees Celsius.  Although warmer in the summer, reaching a peak in September, it rarely approaches 20^o C.  Bearing in mind your normal core temperature is 37^o C, the difference between your temperature and the sea’s is huge, whatever the time of year.  The bigger that difference, the more quickly heat energy escapes from your body into the water.

People think that swimming and thrashing about will help you keep warm if you fall in.  Wrong. Moving your limbs in effect makes water flow over them, which in turn increases the amount of your skin exposed to the water each second, effectively increasing your surface area extracting more heat out of you.  Think wind chill, but in water.  This is why the RNLI advise you to move gently and preferably curl up into a ball to reduce your surface area exposed to the cold water.  Be aware that children’s bodies have a larger surface area compared with their weight than adults, and they will lose body heat even faster.

It gets worse. Physics will tell you that heat is conducted far better in water than air, which means that heat loss from your body is 20 to 25 times faster in water.  That explains why people get cold so quickly when immersed.  The clothes you are wearing will influence how cold you get.  Summer boating in T shirts is great until you fall in. 

Hypothermia is clinically defined as a body core temperature of 35⁰C or less.  One of the first signs of developing hypothermia is the inability to control movements of your fingers, hands and limbs.  Don’t expect that someone who has fallen in can necessarily help themselves to get out. If it is you, then don’t be surprised if you can’t grab that rope that has been thrown for you.  The brain is part of your body.  When that gets cold, it doesn’t work as well.  You will find it difficult to think, communicate and may fall unconscious.  If that happens you are severely hypothermic.

All this assumes that you have survived the initial falling in without getting Cold Water Shock.  This kills those people who get a severe body reflex reaction to sudden, perhaps unexpected cold-water immersion.  The heart and circulation go into overdrive, which itself can be fatal.  Worse is the uncontrollable gasp reflex that can mean you inhale large volumes of water, then drown.  This is why the RNLI advise people to avoid gasping, remain as calm as possible and turn on their back and float instead.

National Coastwatch watch-keepers and all HM Coastguard’s teams take “persons in the water” situations very seriously.  So should you.  A person who falls in the water is a person in grave and imminent danger requiring immediate assistance.  If you witness this, dial 999 and ask for the Coastguard who will task the Search and Rescue Services.  If you are on a boat, make a Mayday call on distress VHF channel 16.  Also, if you are boating always wear a lifejacket; it could save your life if you happen one day to be the casualty.

 New 'Island' near Hurst Castle... Dont Get Caught Out !

There have been changes at Hurst spit at the western entrance of the Solent.  A new shingle bank has formed and is fully visible at low tide. The “island” has gradually built up over the last few months to the east of historic Hurst Castle. The new shingle bank is in an area where many boaters entering the Solent against the ebb tide, having successfully negotiated the Trap,  will turn north to get out of the strongest tides, particularly if heading  in to anchor or are destined for Keyhaven or Lymington.  

 

It is believed that the shingle bank has formed naturally as a result of work to protect the castle from coastal erosion after one of its walls collapsed in 2021, since when many of tonnes of shingle have since been dug up from the seabed to bolster Hurst Spit. The excavations have altered the tidal currents and conditions which in turn has moved the shingle about, causing the new bank to form.

A lot of boaters out there won't be aware of this change, and at high tide, the water is going to be much shallower. The potential is for boats to go aground as it would be easy to hit the new bank when entering the Solent using a chart plotter or even using previously good pilotage marks. In darkness or poor visibility or rough conditions, the risk increases

Some local sailors have visited and  explored the bank and say it is, about 100 metres long and 20 metres wide.

The RNLI and others are spreading the word that there has been a change. Awareness is important to minimise the risk to small boaters.  The shingle bank is continuing to change size and location, and had made the water "considerably shallower.  Seafarers have been told to be "extra careful" when navigating around the spit.

Drone footage of the new bank and photographs has been published on social media. There have been updates to some chart sources, but not all. Existing nautical charts would not show the formation so should be considered "inaccurate”

An associate professor in physical geography at Bournemouth University believes the phenomenon may have been caused by English Heritage protecting the Hurst Castle, which was built by Henry VIII as a fort to protect against a French invasion.

Dr Luciana Esteves has said: "Hurst Spit is artificially maintained, with a lot of shingle added over time. Sources indicate that 7,500 tonnes of shingle were added to the edge of the spit after the damage to the wall of Hurst Castle in 2021.

Head of hydrography at the Maritime and Coastguard Agency, made it clear that the position of the shingle beach in the area changes constantly. The recent coastal defence works to protect the castle will also have altered the tidal currents and conditions, causing a localised change in sediment transport.

The MAC have surveyed this area in the past and we work closely with colleagues at the Channel Coastal Observatory who have been monitoring Hurst Spit and the frontage around the castle for 30 years.

It is understood that the data shows that the new spit is still within the footprint of the beach."

It is not unknown for new shingle banks and Islands so appear in the area. Many local small boaters will  recall that more than ten years ago a new “island” appeared to the west of the southern end of the Shingle Bank  and was easily visible from the mainland at low water. This bank has slowly disappeared and no longer causes a hazard to small boats.  

 

UPDATE !

 

This revised Navionics chart shows the new Lentune Island off Hurst Point...

A Quiet Time Of Year

You would be right in assuming that the activity of NCI Gosport slows down somewhat at this time of year.  The short days and poor weather of January and February drastically reduce the amount of leisure traffic in the harbour and the Solent.  But you would be wrong to think that we close down or become completely dormant during these months.

To begin with, the NCI Gosport lookout station was fully crewed during this time; a total of 59 days, operating a daylight watch with two watchkeepers on duty amounts to 826 person-hours of work.  [About one third of our watchkeepers are female.]

During that time our training team were involved with the training of seven new volunteers, and that included running three or four evening sessions for them as well as the ‘on the job’ training.

Training doesn’t stop with new volunteers though, as every watchkeeper stands a watch with a trainer to do a ‘refresher’, ensuring that skills and knowledge are still up to scratch.  The trainers do this for each other as well.

Outside of training and refreshers, watchkeepers still did their normal tasks in January and February, observing and logging…

… 366 licensed fishing vessel movements (such vessels are regarded as particularly vulnerable).

… 64 other vulnerable vessels such as foreign yachts, kayaks and jet skis that caught the watchkeepers eyes for some reason or other.

…  44 military vessels and 60 lifeboat and Border Force movements (which we just like to keep a note of, even though they are not regarded as vulnerable).

… made 161 status, weather and closedown broadcasts on VHF channel 65

… responded to 95 radio check calls on VHF channel 65

… recorded 236 sets of weather observations

It’s good to know that there were no significant incidents recorded during these months- it means that in our watch area no-one got into trouble.  We did report a SART activation to HM Coastguard though (it turned out to be accidental), and told the Portsmouth Community Wardens about a lifebuoy that was washed up on Southsea beach (presumably having been parted from it’s stand in the area of Clarence Pier).

Let’s not bother to mention the two meetings of the management committee, two meetings of the training group, two general training evenings that everyone who can attends, or the visits to the station from local Councillors, donors, or other NCI stations.

Yes, it certainly was a quiet time of year.