Sea trout crop up fairly regularly along the coast from Lee-on-the-Solent to Southampton water, presumably migrating back to the river of their birth. First catches occur from early April onwards, coinciding with the increase in angling numbers as the new season begins.The fish appear to come close to shore as they travel along the coast, feeding on the incoming tide. Sea trout are also seen in Chichester Harbour from time to time but not in the numbers experienced around the estuaries on the open coast.
Numbers reach a peak in late August/September when some sizeable specimens can be seen leaping high from the water at low tide.
My encounters with sea trout have been by accident when fishing for Mullet, rather than targetting them specifically, which would be a hit and miss affair. However, when a shoal of sea trout does appear, you will soon know about it. They can be aggressive feeders and race to grab a fly (especially a red flexi-floss bloodworm). The fish I have connected with ranged from 3 to 6lb in weight and gave a fantastic account of themselves in the shallow water, coming a close second to Mullet in fighting ability.
The lower reaches of the Test have some noted sea trout pools which may offer more reliable sport than coastal marks.
Best of luck in your venture.
Colin Macleod