MUTINY ON THE BOUNTY was such a success on its recent ABC release that filmgoers have been clamouring for another amazing sea adventure. Carry On Jack is more amusing than amazing and more of a misadventure than an adventure, but nevertheless it carries on the cinema's good seafaring tradition.

On evidence of its first few minutes, anyone not knowing what to expect of a Carry On (is there really any such person where English is spoken?) would be excused for mistaking this latest in the series for a drama. Not only do the credits unfold against a background of paintings of naval warfare and hazard, but the opening scene depicting the death of Nelson begins in all seriousness. I won't risk spoiling your pleasure by telling how neatly the film switches from drama to comedy that never lets up; I will just say that it makes a highly original beginning to a highly diverting film.

Very soon we are transferred from Trafalgar, darting to Dartmouth Naval College to see the First Sea Lord (Cecil Parker) present a midshipman's sword to the most backward cadet. He is Albert Poop-Decker (Bernard Cribbins). He goes to Portsmouth to join HMS Venus, a frigate due to sail for the Spanish Main. He spends his last night ashore in search of the sort of pleasures he'll be missing at sea, and descends into a dubious hostelry revelling under the name of " Dirty Dick's."

He gets on famously with Sally, the landlord's daughter (Juliet Mills) and suspects no ulterior motive when she invites him to her bedchamber. But once they get within striking distance of " X" Certificate behaviour, Sally strikes him on the head, and when he regains consciousness both Sally and his uniform are gone.

He dons one of Sally's dresses in which to get away, and runs straight into the hands of naval officers press ganging poor wretches into service on the Venus, of all ships! They believe that Albert is trying to evade them by feigning a disguise and ignore his protestations that he is a midshipman assigned to their own vessel. They drag him off, at the same time bagging a weedy individual (Charles Hawtrey), who is Walter Sweetly by name and cesspool cleaner by occupation.

Once aboard the Venus, Albert is surprised to find that they already have a Midshipman Albert PoopDecker, and is even more surprised to find it is Sally masquerading. When she gets the chance, she sneaks into his quarters to explain her duplicity. She has insinuated herself aboard the Venus to get to Spain where her lover is a sailor held captive. Albert agrees to keep her secret, which means that life is unnecessarily hard for him as the First Officer (Donald Houston) and the Bo'sun (Percy Herbert) try unsuccessfully to make a seaman of him.

Bumbling along in command of the ship is Captain Fearless (Kenneth Williams), who has brought along a cow, Emma, to provide milk for the men instead of rum. When he turns tail on an enemy vessel, the crew decide he'll have to go, and they put into operation a cunning plot to frighten him into leaving the ship in an open boat wirh Albert, Walter, Sally and the cow.

The Fearless foursome are left to face whatever adventures lie ahead. And there are plenty! I am tempted to tell you how they catch up with the Venus in Cadiz harbour and manage to reboard her while her crew is ashore forcing the Governor to surrender the Spanish fleet. And how, sailing the Venus home by themselves, our gallant quartet unwittingly sink five Spanish ships while below decks performing an operation on Captain Fearless. And how. . . But I must leave the rest of this nautical nonsense to your surprise and unbridled mirth.

Charles Hawtrey and Kenneth Williams are in the cracking Carry On form that comes from appearing in seven and five of the series respectively, and they are able-bodiedly supported by new recruits Bernard Cribbins and Juliet Mills. Amid the-barrage offarcical situations, Donald Houston and Percy Herbert manage to contribute first-rate dramatic performances as the First Officer and Bo'sun respectively, without letting their faces slip. Life aboard the Venus is vastly different for Percy Herbert from what it was on the Bounty!

Jack, which is in colour, is the eighth in the Carry On series, and there's a ninth on the way.