Saturday, April 30, 2011
Tuesday, September 7, 2010
side scan sonar Images from low resolution 220khz home made fish.
Here is an image taken using the sidescan sonar, now fully functional for the first time!!
The software has saved the images a little bright so work is needed but you can clearly see the wreck of the blazer shortly followed by the serica along the right hand side from centre to bottom left.
HMS Blazer was an armaments tug of roughly 280 tons. She sank on the 10 November 1918 close inshore near the Conger ledgers just off the garisson walls on St Mary's the Isles of Scilly. She is mostly broken up but still lies in a ship like shape with her bows whole and her hull showing up on the sonar as boat shaped.
The Steam ship Serica foundered on Serica rock just off the Steval off the Garisson walls St Mary's, Isles of Scilly on the 24 November 1893. She had just avoided sinking and was taking shelter in the roads.
We are now viewing several weeks worth of data taken of the whole of Scilly and will return with a high resolution 700kHz version of the same fish design shortly. Inspiration for the fish came from Sture Hultqvist, now not with us but his tales of engineering and sonar hunting lead me to build my own.
The side scan sonar is towed behind the boat and looks out each side to left and right. It misses directly under the boat because of this but gives an image in the same way light does with a sundial giving a shadow except using accoustics. The lower th efish th ebigger the shadow and the brighter the reflections. The higher the frequency the higher the detail so long as the fish is long enough. short arrays do not always give high detail.
CLICK FOR BIGGER IMAGES
HMS BLAZER
Monday, August 9, 2010
Back now
Im back for now to edit films, repair sonar equipment and earn some money.
Ill keep this site up to date with news of the next trip or expediton when I can and post some photos and videos in due course.
Thanks for looking
Robin
Ill keep this site up to date with news of the next trip or expediton when I can and post some photos and videos in due course.
Thanks for looking
Robin
Wednesday, July 14, 2010
Dolphins and Basking sharks!
The two days before I left for home I was lucky enough to see a bottle nose dolphin riding the bow waves in front of our boat. I filmed it in 720p HD and 1920x1080 full HD. A stunningly beautiful and friendly creature.
Following this the day before I came back we were surrounded by Basking sharks.
I started to film them from the bow and had an idea to try and film them underwater.
Although my camera was not set up and needed cleaning and adjusting I threw it together in seconds and jumped in.
Several hours of frustrating and tiring swimming with a large camera the size of a microwave oven was had trying to film the creatures but they were accompanied by juveniles who were scared by the boats of us and now several dive boats getting closer and closer. We left them alone prefering not to drive to close. On spotting another about 28-25 ft long we tried a new tactic of sitting and waiting. We got closer and observed them but swimming in the open water with these graceful freight trains of the sea even with a snorkel and mask is hard. The final attempt eventually paid off when we found a lone pair away from the islands towards Samson less perterbed by the company. using my 3m inflatable tender we used the 2.5HP engine to quietly and slowly get closer to them and I slid in at the last minute.
The following was grabbed from my video camera and shows how magnificent they really are.
The most amazing experience of my life then occured as they swam towards me out of the gloomy green water hoovering up the plankton with their large open mouths.


If I had been prepared I could have done much better but the split second decision to jump in with my kit was one of the best I have ever made giving me new respect of the oceans creatures and admiration for their grace and beauty in the water.
Following this the day before I came back we were surrounded by Basking sharks.
I started to film them from the bow and had an idea to try and film them underwater.
Although my camera was not set up and needed cleaning and adjusting I threw it together in seconds and jumped in.
Several hours of frustrating and tiring swimming with a large camera the size of a microwave oven was had trying to film the creatures but they were accompanied by juveniles who were scared by the boats of us and now several dive boats getting closer and closer. We left them alone prefering not to drive to close. On spotting another about 28-25 ft long we tried a new tactic of sitting and waiting. We got closer and observed them but swimming in the open water with these graceful freight trains of the sea even with a snorkel and mask is hard. The final attempt eventually paid off when we found a lone pair away from the islands towards Samson less perterbed by the company. using my 3m inflatable tender we used the 2.5HP engine to quietly and slowly get closer to them and I slid in at the last minute.
The following was grabbed from my video camera and shows how magnificent they really are.
The most amazing experience of my life then occured as they swam towards me out of the gloomy green water hoovering up the plankton with their large open mouths.
At least twice my size they looked tiny in the viewfinder of the camera but the amazing Fathom lens of my video camera captured them from full wide to up to six inches from the lens! Daunting enough was the fact I was swimming several miles out to sea with a snorkel and just a single boat within 100m. To follow was the imense size of these miracles of nature, perfect in every way and gliding through the water with minimal effort irrespective of the drag from their open mouths and size close to two cars.

If I had been prepared I could have done much better but the split second decision to jump in with my kit was one of the best I have ever made giving me new respect of the oceans creatures and admiration for their grace and beauty in the water.
Thanks to todd and carmen for hours of patience, good boat handling, local knowledge and determination to help.
Thursday, July 1, 2010
Foggy day.

Today is drizzle rain fog and mist. Not good but after several weeks of oven like temperatures its a welcome change. Knowledge of me and the london divers long suspected piracy has spread and is now a humorous talking point by everyone. Walking down the street I was accosted by over nine people one giving me a jolly roger flag! Im also popular with the police who ask about the latest stories of wrecks and treasure!
Yesterday was fun!

The diving was great and weather hot but on returning back I got a call from the police. Apparently some uneducated locals had reported me for diving an historic protected wreck site called the Bartholemew. The site of the Bartholemew is reported to be a fifteenth century cannon site which I have dived on a license before. We were actually diving a wreck we found last year called the Magdeleine. A steam trawler probably of nineteenth century origin with huge boilers and winches which, are not normally found on fifteenth century wrecks! After I explained some history and the historic wrecks act of 1974 they were happy and went off to resolve the matter with the individuals unaware of the charts and rules. Diving was amazing and the guys were pleased to see something close to the harbour with lots of interesting things to investigate. We have some interesting things to reseach and a few artifacts to report and clean up for the museum or a display.
Wednesday, June 30, 2010
Wreckage from the magdeleine

Brass wheels from a telegraph or control lever. On the end is lots of small chain and a lever like a bike brake handle. Spotted by the London dive team, this was being battered and sandblasted by rocks and shail and had big marks on so we though we would lift it to see if we could find any makers identification marks.
Sunday, June 27, 2010
Dredging pendrethen

The water pump in the inflatable tender is used to pump water down to the sea bed to a venturi pipe. This sucks up the sand gently as it is wafted up by hand and leaves the items behind to draw, photograph and measure. The site we were looking into here was the Pendrethen wreck site and Inisidgen cannon site.
Friday, June 25, 2010
Side scan sonar towed array on the boat.

The side scan sonar fish, as it is known, is towed behind the boat at speeds of three to eight knots. It digitises the sea bed and produces an image up to 400m wide called a swathe. Higher frequencies give increased detail or resolution but less range. Today we found some good hits but enterpreting the data takes a lot of time. Eventually we will mosaic the data to give a coverage of the whole area for analysis and archives.
This one was developed by Myself and a few friends I used to work with.
It is a 220kHz system using a programmable processor to digitise signals and send them to the PCs USB port. The software gives lots of tools for analysing th data, recording it, zooming and measuring whilst correcting radiometric and geometric errors.
What looks like a brass deck drain

Diving off the retarrier ledges this was concreted into the bottom. There are several wrecks here most notably the Schiller, a German transatlantic steam packet wrecked on the 7th of May in 1875 with a loss of 335 lives. It was coined the victorian Titanic in recent times and is well broken up by harsh tides and heavily salvaged by visitors and locals alike so archaeology is difficult. It holds some nice cutlery and rumours of coins with good examples of engineering from Glasgow and England! All in all a nice find with something to report to the receiver of wreck on returning.
Thursday, June 24, 2010
Off to the western rocks.
London spidge SAC out deciding where to dive while trying to avoid seasickness. A great bunch and a good laugh. After fixing their boat a few years ago we became friends and now have a regular meet each year.
Wednesday, June 23, 2010
Scilly day 5 breakfast!

After a few days relaxing im just finishing breakfast while waiting for a group of divers from london to arrive. The plan is to look at a few sonar hits, dredge a site to uncover the extent of the wreckage to see if we can identify it and have some fun making a new DVD. It will be good to see them again. I made friends a few years ago after repairing their boat engine and have kept in touch as we all have a great time and similar interests. The weather since has been very inclement over the past few years but we are hoping for better this year. Fingers crossed this but so far so good!
Monday, June 21, 2010
A stunning evening.

After two dives and some wildlife watching the light put on a stunning show for us where cormorants, razorbills, puffins and shags gracefully glided over the ironed sea and the sun reflections glistened off the rocks and wavelets. I am having problems with my phone key pad but will try to sort tonight.
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