Solution by “Kedenan ", played on the Amstrad CPC

S. S. SE. EXAMINE SINK. GET SOAP. EXAMINE SHOWER. UNDRESS. TURN KNOB ON. RUB SOAP. DROP SOAP. TURN KNOB OFF. DRESS. NW. EXAMINE WARDROBE. GET BOX. N. NW. TALK TO NOEL. GIVE BOX TO NOEL. TALK TO CUSTOMER. EXAMINE KEY. READ NOTE. E. EXAMINE POCKETS. GET POUND. CLOSE DOOR. BUY SAUSAGES. W. SE. W. PUSH DOOR. N. UNLOCK DOOR. DROP KEY. N. OPEN FRIDGE. EXAMINE CUPBOARD. OPEN DRAWER. GET KNIFE. S. S. S. EXAMINE SOFA. GET MASK. N. W. GIVE SAUSAGE TO DOG. GET CAN. EXAMINE CAN. E. N. N. GET RUDD. S. S. E. E. E. GET ROD. GO INTO BOAT. EXAMINE ENGINE. POUR PETROL INTO TANK. DROP CAN. PULL CORD. S. W. SW. PUT RUDD ON HOOK. CAST IN. REEL IN. GET PIKE. EXAMINE PIKE. NE. EXAMINE PIKE. GUT PIKE WITH KNIFE. GET LURE. DROP KNIFE. E. N. W. LEAVE BOAT. W. NW. GIVE PIKE TO NOEL. GET DETECTOR. GIVE LURE TO CUSTOMER. SE. E. TURN ON DETECTOR. SEARCH. DROP DETECTOR. GET ANCHOR. GO ONTO BOAT. PULL CORD. S. E. E. EXAMINE TREE. WEAR MASK. OPEN BOTTLE. EMPTY BOTTLE INTO NEST. DROP BOTTLE. GET GRUBS. W. W. S. PUT GRUBS ON HOOK. CAST IN. STRIKE.

Well done, the tench weighs over 10lbs. You've succeeded where many anglers have failed. Take a bow! You are the supreme angler!