You in with a chance for Gts most time of the year but I would recommend Mar/Apr/May around the Springtides, you want a pushing tide at first Light or last light and hopefully a bit of a South Wind and swell to get the water working and for casting off the Southern side of Hells Gate. Dont bring a peashooter to a Gun fight as the GTs here can be serious! For Charters, contact Graham Pollard at Mozambique Angling Adventures, he is the most knowledgeable when it comes to lure fishing, being popping etc......other operators are Bemugis and Go Azul, but you will pull rappies all morning! Couta are slmetime caught in Hellsgate but for that I would swim a Livebait on a Balloon, last year a 30kg couta was caught in the Channel off the Northern Bank.