Geoff Thomas: Sounds like plenty of fun

Clayton Knowles scored with the first groper. Photo / Geoff Thomas

The divers slipped into the water, adjusted their mouthpieces and their flippers, waved for a second before disappearing.

"They'll come up with some big crayfish," said Murray Knowles as he nudged his 65-foot launch, Kaela Rose, away from the rocks off d'Urville Island, in the Marlborough Sounds.

When you put nine blokes together on a vessel as comfortable as this one, you know you are going to have a good time.

It was an annual excursion for the Christchurch boys, with a couple of Aucklanders for extra spice.

Murray keeps his boat over the hill from Picton and spends as much time on it as he can.

"This is my playground," he said as we cruised up Queen Charlotte Sound. "You can dive for scallops in that bay over there and, when we get outside, we will stop on one of my groper spots. Then we will throw the divers into the water and a couple of the youngsters might go for a hunt tonight."

Murray had returned from the Miami Boat Show to be greeted by the sight of his building in ruins, the result of the February 22 earthquake a day earlier. All of his staff escaped, but the front of the building where he bases his plumbing supply business, Edward Gibbons, had collapsed.

"I couldn't do anything, so I thought I might as well go fishing," he said.

The key to groper fishing is to hit the spot at slack tide so the boat doesn't drift off it and you can get your baits to the bottom. Once the current is flowing, the sinker and baits are swept away and your line ends up angling away from the boat - too far to feel the bottom.

But Murray was right about the divers. I had wondered why they carried such large catch bags clipped to their waist.

You soon learnt why. The first diver up could hardly lift his bag on to the duck board at the back of the launch, and it only had four crays in it. They were huge. The second was empty but the third was packed. The only other place we have seen such huge crayfish is in Fiordland and at the Chatham Islands.

But these d'Urville crays were big bugs. Seriously big bugs. Like most fishermen and divers, these boys guard their spots jealously and with good reason. They once took a guest to a good dive spot and he returned with a bunch of mates and cleaned it out. So they are pretty careful about who they invite and the Aucklanders were a safe bet as they were unlikely to return under cover. You just don't do that to people who look after you, be it hunting, duck shooting, fishing or diving.

Like the big fish which are found in deep water, crayfish grow slowly. These bugs were about 4kg each and probably 50 or 60 years' old, similar to groper or hapuku which grow at roughly a kilo a year and can reach 80kg or 90kg.

So you think carefully about knocking such fish on the head and about taking any more than one or two at a time.

The crays we catch in our waters are technically rock lobster or spiny lobster, and differ from Northern Hemisphere lobsters in that they don't have any claws and are thought to protect themselves from predators by creating a loud screech generated by rubbing their long antennae against a smooth part of their outer shell. This protecting device doesn't always work too well, as big snapper love crunching crayfish in their powerful jaws and they are particularly vulnerable after shedding their shell each year until the replacement shell underneath hardens.

These crays were soon boiling in seawater on the stove while the boys manned the rods over one of Murray's cod spots. The Sounds are famous for blue cod, although some severe restrictions have been put in place to protect the fishery.

But the blue cod soon joined the crays on the dinner plate and, while an evening hunt for the many deer and wild pigs that inhabit this huge island did not bring home any bacon, the groper hole produced the goods the next day.