WE’RE in the boat at 7.30am and a blue-hazed limbo beckons. The hopefuls — Nick Moore, Buj Statley and myself — are up front. Justin Anwyl, our guide on Chichester Harbour for the day, is on the rudder.

The West Sussex sky is blue, streaked white. The long, thin crayon lines of gravel banks and promontories — greys and greens, ochres and browns — recede to a low horizon. Our wake rolls and glints. A moored yacht curtsies. We make small talk over the engine noise and ponder our chances.

It is bass, the possibility of a big bass on a fly, that has brought us here. Most sea fishing is about heavy rods, thick lines and weights that could double as anchors. But, of late, a growing minority has been using light, wristy trout gear to catch sea fish from the shore.

The well-heeled have been fly-fishing in the sea for years in the tropics, wading the flats for bonefish and permit. This is the home-grown version. Fly-fishing for bass around the shallows of the South, the South West, Wales and elsewhere is still cultish but edging mainstream. Like Nick and Buj, I want to give it a try.

By 8am, Justin has us in the middle of nothing, on the far side of nowhere. We are utterly alone, belly-button deep, seemingly miles from the nearest shore. The bass will be hunting fry moving in and out on the tide. The large fish will be circling them, waiting to strike. Justin’s job is to move with the tide and keep us where the fish are likely to be. Our job is to cast as far as we can and to bring the 2in flies back in brisk fits and starts to trigger a predatory reaction.

Two years ago, when he was 35, Justin gave up a big-money job as a bond-broker in the City to come here and “get a life”. He has an abrupt way of giving directions, but he clearly knows what he is doing. It is why 300 clients have booked him at £80 apiece this year. It is why we do as advised.

It is astonishing how quickly it happens. Following the tide, yomping between marks, we are pretty much a group. Once fishing, bonds melt and silence enfolds. In no time, each of us is cocooned, each of us is in his own world of water and light, wind and wave, rod and line, fly and hope.

We all want a sizeable bass, a two-pounder-plus. Justin makes no bones about the odds. Once Chichester Harbour was a hot spot for such fish. Now, thanks to commercial netting and a size limit that allows fish to be taken before they can reproduce, the inevitable has happened. The commercial fleet has trawled the heart out of the stock. There are plenty of bass about but they are mostly small. Just one fish in 20 gets over 1lb, just one in 30 or 40 will be much bigger.

We fish and yomp, fish and yomp as the tide ebbs and turns and the wind gets up. By 11.30, we are on our third or fourth mark. Now, what appears to be an apartment block, square and grey-plumed, is on the skyline beyond the Isle of Wight. A powerboat is playing ducks-and-drakes with a swell. An enormous bubble is drifting under my rod, bending light. Inaction is sapping my concentration — and then suddenly we are among them.

First we see furrows and splashes, then Buj’s rod goes over, then mine, then Nick’s. For maybe 30 minutes we get take after take, bang-bang-bang, just like that. They are bass all right, bristling and aggressive, tight-muscled and bright silvered. But small. These are the school bass, the 19-out-of-20 bass. It is the 20th, the 50th, the 100th bass we want.

We get what might be the 200th, the 300th. It comes as we scrunch and splash back to the boat and home. I hear “Big fish! Big fish!”, see Justin and Buj pointing, then Justin’s fly is dropping beside the shadow he has seen on the sand, 15 yards ahead of him. The take is instant and savage, the rod goes down as though hit by a sand-bag and Justin is sploshing after a bow wave headed for the Antipodes, for all the world as if towed.

The fish does not have surrender in it. Several minutes later, when it comes to hand, it is still all aggression and high, spiked fins. It is an absolute stunner, a good five-pounder, the fish of many a bass angler’s year. We photograph it, Justin lowers it to the water and the fish resumes its deadly game of mouse and cat with the nets.

Anglers have been fighting to conserve bass for years and now can see their own tide turning. They are expecting a higher size limit to be announced before long. After that, they want all netting stopped. If they can succeed, if that one fish in 200 can be made one in 50, if that one in 20 becomes one in half a dozen, saltwater flyfishing will move from cult to boom. It is a wide-open space, worth watching.

• Brian Clarke’s monthly fishing column will appear on Monday

  IT’S CATCHING
  HOW TO HOOK A BASS

• TIPS: Bass are essentially a summer species and are best caught on the fly between May and October, when they are at their fattest. Tide tables are a must and a day with a guide (Justin Anwyl is on 01243-785496) will build confidence.