The Open-Water Temperature Thread

[Wildswimmer]

River Mersey today - upper estuary at Runcorn, low tide.

Water temp in waist-deep channel: 16.9C
Surface mud temp: 21.4C
Deep mud temp: 15.9C
Air temp 20C @ 4pm.

Wildswimmer Pete

[richard-broer]

The Old Rhine river near Bodegraven 16,5 digital though not the standard 40cm deep. Air temperature tropical too: 25+
The serious distance training will start now.

[Wildswimmer]

River Mersey, New Brighton, 11.5C outgoing tide.
Air temp 21C at lunchtime and hotter still during the afternoon.

The RLNI and Coastguard rescue teams were undertaking a mud-rescue drill in a deep mudbank further upstream. They very nicely allowed me to go into the mud (in my cozzie) to take pics of the proceedings. I had my dive camera so no problems with it getting muddy. Should I have got some decent shots I'll post one on the "Pics of Places You Have Swum" thread.

Wildswimmer Pete

NB Yes, I had another cold swim afterwards to wash off the mud.

[Leprechaun]

Originally Posted by Wildswimmer

River Mersey, New Brighton, 11.5C outgoing tide.
Air temp 21C at lunchtime and hotter still during the afternoon.

The RLNI and Coastguard rescue teams were undertaking a mud-rescue drill in a deep mudbank further upstream. They very nicely allowed me to go into the mud (in my cozzie) to take pics of the proceedings. I had my dive camera so no problems with it getting muddy. Should I have got some decent shots I'll post one on the "Pics of Places You Have Swum" thread.

Wildswimmer Pete

NB Yes, I had another cold swim afterwards to wash off the mud.

Looked absolutely disgusting - like you were clearing out some old sty!

Went down to Hayling Island today - just under an hour in 12C. Looks like this is now the preferred training location (only 40 miles from Guildford) rather than the mega trek to Dover.

Three of us in the water, solves any safety concerns about solo swimming and we covered a couple of miles perhaps.Lovely day, no-one else in the water and had a about a 3/4 mile with tide at one stage.Does it get any better?

Really feel for all you pool swimmers, you dont know what you are missing

[Wildswimmer]

Originally Posted by Leprechaun

Looked absolutely disgusting - like you were clearing out some old sty!

If you like playing in estuaries you have to get used to the stuff. Anyway a swim washes it off bare skin in seconds. Believe it or not there's little or no smell from the marine mud in the Dee and Mersey estuaries. The main reason the crews had to wear all their gear in the warm weather is because most mud rescues seem to occur in winter and generally involve wildfowlers, anglers, birdwatchers and others dressed in heavy, non-buoyant clothing. It's very easy (albeit messy) for a swimmer to extricate himself from summer-warm mud - and equally easy to wash it off afterwards. I'll be posting pics of a demonstration of self-rescue from mud as soon as I can arrange for a friend with good zoom facilities on his camera to come along and take pics of the escapade.

Meanwhile, River Weaver (Frodsham) today, a very creditable 17.7C (63.9F). And I'm glad to report that after watching me happily swimming, several local kids stripped off and followed my example - as they used to do years ago before the Safety Gestapo demonised wild swimming. The water temp was well above the critical 15C so they were in no danger.

Originally Posted by Leprechaun

Really feel for all you pool swimmers, you dont know what you are missing

Amen to that!

Wildswimmer Pete

[happySwimmer]

Originally Posted by Brick

Anyhow, by leaving my aquarium thermometer floating at the edge of King Lear's lake for a bit on Friday 6th April 2007, the result was 12C.

Originally Posted by Wildswimmer

Surface temp using digital thermo: 15.2C. Deep water measured with spirit s/pool thermo

What is the difference between the thermometers mentioned here? What is the best for measuring water temperature? Would I need different ones to measure surface water and deep water?

....and finally - where do you buy them and what sort of price are they?

Thanks for your help

Marian

[Wildswimmer]

Originally Posted by happySwimmer

What is the difference between the thermometers mentioned here? What is the best for measuring water temperature? Would I need different ones to measure surface water and deep water?

....and finally - where do you buy them and what sort of price are they?

Thanks for your help

Marian

My digital thermometer is highly accurate but being electronic only the probe can be immersed, meaning I can only take a surface reading with it. This is the one I use for my records.

A swimming pool thermometer is basically a spirit thermometer with a little bucket that retains a sample of water when removed. This type of thermometer can be submerged (as can Brick's aquarium thermometer) so can be used to take both surface and 1 metre depth readings which is the standard procedure here in the UK.

Digital thermometers are available for anything from a tenner to a few hundred quid. Swimming pool thermometers cost around £10 - £15, and for general use I'd recommend one of these.

Wildswimmer Pete

[Brick]

Originally Posted by happySwimmer

What is the difference between the thermometers mentioned here? What is the best for measuring water temperature? Would I need different ones to measure surface water and deep water?

I consider buying an aquarium thermometer to be a mistake. I wouldn't advise anyone to get one, as it seems to take a long time for the temperature to stabilise. The bulb with the alcohol in it is surrounded by small lead balls rather than being directly connected to the outside world. Also, they float, so to measure the temperature underwater would require holding it down. So far I've only measured temperature by putting it into some location (weeds, tree roots) where it couldn't drift away and leaving it there for a while.

It might be possible to engineer a better thermometer for readings by super-gluing it to a rock or something so that it sinks.

They are cheap however. Mine cost less than two quid, and it should be possible to get something for about a quid or so if it was actually worth searching around for a cheap one. I won't insult anyone's intelligence by saying where you can get one.

[happySwimmer]

Originally Posted by Brick

It might be possible to engineer a better thermometer for readings by super-gluing it to a rock or something so that it sinks.

I'd probably drop the rock on my foot or superglue my finger to the rock!

Originally Posted by Brick

I won't insult anyone's intelligence by saying where you can get one.

Thanks I think I can guess.

Marian

[Brick]

River Biam, about 4:15pm (I must get around to taking my lunch break at a more reasonable time). 16.5C. I'm not sure my thermometer is good enough for .5C increments, but it seemed slap bang half-way between 16 and 17.

If I get in early tomorrow so that I can take a guilt-free longer lunch I might be able to get to the Sence. I've never had a good close look at it, and on the weekend someone from a wildlife organisation told me that it had been recolonised by freshwater mussels. Indicating that it's getting cleaner.

[Wildswimmer]

River Weaver tonight: 17.3C (63.1F)

Reading taken near bank with digital thermo. I couldn't make a deep-water reading as I wouldn't have been able to see the pool thermometer in the dark - today's was a night swim.

Wildswimmer Pete

[richard-broer]

My thermometer leaped to a 18.2 today! It's like on of Wildswimmers digitals: not suired for the deep water. FINA temperatures are to be measured at 40cm. So I have a non-digital one used by anglers for carp fishing at depth. That sinks quite well. Beacause of the metal casing. So I put it on a fishing line and attached a float too. I adjusted it to 40cm depth. OK... that's still balmy at 16.7C.

So no problems for a big swim this week!

What do you do to sustaine the energy for distances of 6km/1.15hrs and more? I have heard of people that swim a 10Km and much more without food or drink. Is that sane?

[Wildswimmer]

River Weaver this afternoon: Near bank, taken using digital thermo from jetty: 16.7C (62.0F).

Deep water midstream, using pool thermometer Surface:18C (64.4F), 1m depth: 18C

Wildswimmer Pete

[Brick]

River Biam today, at about 1:30pm. 16C. Felt a bit warmer than Brighton at the weekend, though I only waded across to see what was causing some commotion in the shallow gravel on the other side. Whatever it was, it disappeared before I got there. I didn't swim.

[Wildswimmer]

River Weaver this afternoon: Surface from jetty (digital thermo) 17.4C (63.1F)

Spirit thermo in deep water: 18.5C both surface and at 1m depth.

I also noticed some small patches of that brown floating algae so it's obviously starting to grow with the higher water temps. I was relieved to find they weren't refugees from the Firth of Forth. The river water has also lost its muddy appearance and is now clear with a faint greenish tint.

Wildswimmer Pete