SITTING ON A BOAT ON A SUNNY DAY, divers are slowly kitting up as seabirds swoop from the cliffs on the north side of Skomer Island. A scruffy grey Avon Searider cruises in, carrying two occupants. They are not dressed for diving, but wear green T-shirts, orange fishermens overalls and boating lifejackets. The RIB bears the legend: Skomer Marine Nature Reserve.
Hello, your boat looks familiar. Can you remind me which club youre from The divers are being skilfully interrogated about their numbers, how long they are there and where they are diving. Equally subtly, they are reminded about the diving and boating rules of the marine reserve. If you are new to the area, you would be handed a set of information leaflets, including details of slack water times around the island.
The crew are Phil Newman and Kate Lock, marine conservation officers for the Skomer Marine Nature Reserve. For many divers this is their only contact with the policing of the reserve, except perhaps for watching Phil and Kate come in and out of the beach at Martins Haven.
But this public contact with visiting divers is only the tip of what is involved. Having been a regular visiting diver for several years, on a busy June weekend I joined Phil and Kate on patrol, assisted by Saba, the boxer dog Kate was minding.
Its a perfect day, so we head straight out across Jack Sound to North Haven at Skomer Island. Kate makes notes of lobster pots left by local fishermen. Phil explains that commercial fishing within the reserve is limited to a few locals who have run pots since long before the reserve was established.
We find one of them in North Haven, retrieving his pots. Some are a bit scummy and Phil comments privately that they have been left down too long and there is too much floating line out. We approach the boat to say hello and ask about the catch. Its all part of recording what goes on in the marine reserve.

Next stop, a couple of dive RIBS tied off to a mooring. Regular weekend visitors, the occupants know the rules. A couple of divers are preparing to do some training exercises in the shallow water of the bay and the others will be diving the wreck of the Lucy later.
Before leaving the bay, we idle across to the landing stage for Skomer Island, so that Kate can make a brief diversion ashore and deliver the islands mail. Then, back on patrol, we say hello to a couple more dive boats on the north side of the island before continuing round the Garland Stone. More strings of lobster pots are counted in shallow water beneath the cliffs.
As we round the Pig Stone at the south-west corner of the island, Kate spots a tangle of bright orange fishing net further out to sea. We stop to recover it, freeing a dogfish that was entangled but still alive.
While halted, a message comes in on the marine VHF radio. Juan Brown, the warden from Skomer Island, is out in his boat counting birds on the Garland Stone and has seen us passing.
He had found the decaying remains of a turtle and knows it will be of interest to the marine reserve.
We double back and locate the turtle. The remains are in a sorry state, barely recognisable if not for the shell. Phil and Kate inspect the body for any sign of cause of death, but nothing is obvious. Juan takes a section of spine as a means of identifying the species and the carcass is left as food for the gulls and fish.
We round the south side of the island to South Haven. A blue RIB from Pembrokeshire Dive Charters has a tour party on board Ð not divers but tourists out for a trip round the island.
We stop to greet them, and though they have a qualified biologist guide on board, Phil and Kate are invited to talk to the passengers about the underwater side of the marine reserve. Phil is a permanent employee of the Countryside Council for Wales, but Kate is on a part-time contract and fills in with some guide work on the RIB tours from time to time.

On the other side of the bay, a line of yachts is tied up to moorings. All part of monitoring the use of the reserve, we drive over to get a count of the number of people on board and record where each yacht is from. One lot are well into the G&Ts already, and its only 11am.
Our circuit of Skomer is completed by cutting through Little Sound back to the north side. We tie off to a marker buoy about 100m offshore to collect data for some ongoing projects. Sensors are lowered to measure water temperature, conductivity and salinity at 5m depth increments.
Perhaps most interesting for a diver is a measurement of visibility. A white disc is lowered into the water until it can no longer be seen.
Visibility is measured at 7m, above average for the time of year. The best Phil and Kate have ever measured is 11m.

The scientific work doesnt stop at the surface. A few days later, I board the NMR hardboat Skalmey to join the team on a dive.
All diving operations are carried out under the HSE agreed code of practice for scientific and archaeological diving projects, which requires at least three divers, so local fireman and part-time voluntary assistant Steve Myatt joins Phil and Kate to complete the team of supervisor, diver and standby diver, in this case an underwater buddy. I am part of a separate diving team, so bring my own buddy along.
Todays task is to measure an area of gorgonian seafans on the north wall. Such measurement is an ongoing project, with several mapped groups of seafans being surveyed regularly.
Our main tools are a Nikonos camera system on an aluminium frame and a blackboard with a grid marked on it. You sandwich the seafan between frame and blackboard to photograph it from a known distance against the grid background. Over a series of images, growth of an individual can be measured and any disease or damage detected.
Under water and in practice it is far more complicated. In addition to the camera frame, Kate is carrying a slate with the site map and record form. She knows the site well and can virtually identify individual seafans from memory.
The camera frame acts like a sail in the gentle current, making it very difficult to manoeuvre into place without harming the sea fans or other marine life.
Steve has an equally difficult task with the blackboard. Once the photograph is taken, they rotate round the subject to take it again from the opposite side, and Kate records the details.
There are 11 seafans on the route, which allows for a few spare shots on a roll of 36 or to go on and survey a second, smaller site.
Growth of the seafans has been measured as less than 5mm per year, so some of the larger fans could be getting on for 100 years old. As with diving a coral reef, all divers need to take care not to damage or break them.

Next day were out on the boat again. Steve is on shift, so Blaise Bullimore has joined the diving team for the day. He used to work on site as a marine conservation officer, but is now office-based as senior marine conservation officer for West Wales. He enjoys getting back into the field and under the water.
The plan is for Kate and Blaise to swim a fixed transit on the seabed, taking overlapping photographs to build a photo-montage. This is another ongoing project, with the same area being re-surveyed to record distribution and coverage of marine life.
Before they can begin, two ring bolts set in the rock have to be located and a line stretched between them to mark the survey path.
Phil solo-dives to do this, using an SMB as his means of surface location and with Kate fully kitted in the boat as standby diver.
As with any underwater task, it is never as simple as expected. The marker buoy for the site has torn loose, and it takes Phil much longer than expected to locate the first bolt.
He finds the downcurrent bolt first, so has to drag the line upcurrent to find the other one, and then stretch the line tight. Eventually the task is completed, and Kate and Blaises dive goes to plan.
Some of the marine reserve work continues all year round but other work is seasonal, such as counting seal pups in autumn. Towards the seasons end the officers dive to remove the reserves boat mooring buoys for the winter, then dive again to replace them in the spring. Replacing lost moorings is about the only time they get to dive the Lucy, which, Kate confides, sometimes takes longer than is strictly necessary for the task.

Patrol work in the RIB is mostly at weekends and bank holidays, when diving is busiest. Phil and Kate occasionally help out by searching for lost divers and towing in disabled boats; not only dive boats but yachts and fishing boats in trouble.
Back on a busy beach at Martins Haven, they talk to each group of divers, again recording data and informing them about the marine reserve, but also helpful in answering any questions about diving conditions, dive sites and marine life.
If it looks an easy job, driving around in a boat on a nice day, there is more than enough work that visiting divers dont notice. In fact there is so much to do that Phil and Kate would be hard-pushed to keep up if it were not for locals helping out on a voluntary basis. Kate is also the local co-ordinator for Seasearch, the ongoing Marine Conservation Society project to collect data on marine life all round our coastline.
Visiting divers can also help in this. Simple things such as recording numbers of divers, sites dived and a few basic observations are easy enough for any group to complete.
Organising a beach clean-up between dives is something else that requires no training, and during dives you can collect lost fishing line, weights and other submerged litter.
At the end of the day Phil and Kate can show you where to leave the collected bags, though some divers like to hang onto the fishing weights. Sooner or later, they could have enough for a weightbelt.

Photographing a gorgonian, which has to be sandwiched neatly between the camera frame and blackboard, taking care not to damage it
This scrap of drifting net was pulled on board and a dogfish set free
Phil and Kate discuss plans with visiting divers