Pen Llŷn is great for divers because it's a peninsula. We can go diving on the opposite side of where ever the wind's blowing.

On the south side, we go diving around the Tudwal Islands, Hell's Mouth, Seagull Island and Aberdaron Bay. This side can get a bit churned up though because of all the silt. Small, neep tides are always better for diving because the water is clearer.

There are lots of wrecks in the seas off the south side. Most of them have disintegrated but the creatures seem to prefer them to the natural rock, sand or gravel beds. They become artificial reefs.

The north side of the peninsula, from Nefyn up to Porthdinllaen and Bardsey is very rocky. There's a tremendous amount of life down there though and there's a lot of fishing for crabs and lobsters.

We also go diving round Bardsey and to the pinnacles beyond. You've got to get the conditions right there - dive only when the tide's not running because the currents are extremely strong.

We've seen dolphins a lot but the funniest thing is when the seals come and play with you, especially off the Tudwals, Half Tide Rock and Bardsey. They come up and chew your mask and can get to be a bit of a nuisance because they don't want to leave you alone!

We tend to do a lot of drift diving off Pen Llŷn. You don't have to do much, just let the currents take you - you can get up to speeds of 3 or 4 knots! You can cover quite big distances in a single dive, so there's always a buoy attached to a line up on the surface to let the boat know where you are.

Drift diving is the closest thing to flying - you're literally swept across the sea bed without any effort. In fact, some people have become very cold even with protective clothing because you're not really doing any physical exertion.

We sometimes see octopus, although they're quite shy animals. We were drift diving once and passed over an octopus swimming in a gully beneath us, poking his tentacles into holes looking for food. It was very intriguing to see animals in their own world as we drifted by so quietly.

But one of the biggest threats to the area is dredge fishing for scallops. It's destroying so much of the underwater habitat, including the lobster spawning areas which the lobster fishermen look after so carefully.

There are a few special areas of conservation but one officer can't protect all of Pen Llyn, especially when this type of fishing is done at night.

We sometimes see the results of the dredging whilst diving, when the sea bed is destroyed, taking a few scallops with it. It's so disheartening.

People who want to dive, especially round here, must go with other experienced divers. You can't just jump in by yourself, like you can in the Red Sea or the tropics where there's not much of a current and the water is so clear. You can get visibility up to about 15 or 20 metres here, but that's as good as it gets.

As a club, we train anybody who's interested, from beginners to advanced level. We take things gradually so people can build up a lot of experience.

A big problem is when people come back from diving abroad - they've done a bit of theory, done a few dives and suddenly they've got a certificate which isn't up to the British Sub Aqua Club standard. That can be deadly if you haven't learnt how to dive in the sea here.