A/N All charachters belong to HiT Entertainment

Sam, Penny and Ellie lined up in front of Station Officer Steele while he assigned their duties for the day. "Sam, Penny; you are to head over to the Ocean Rescue Centre. Sam needs to keep keep his diving hours up or he will need to retrain. Ellie, you are to stay in the station in case any emergencies come in. You can check the contents of Jupiter's lockers against this inventory". He dismissed the firefighters and they headed off to their respective duties.

Sam and Penny climbed into Venus and headed over to the quay. Ben was already waiting for them. As Penny climbed down from Venus he ran over and grabbed her, kissing the back of her neck. "Get off me" she squealed "this is not the time. We are both on duty. Station Officer Steele would go mad if he saw". Sam smiled at his two friends. They were besotted with each other but he knew neither of them would let it get in the way of their work. "Ok" huffed Ben in mock indignation "I consider myself firmly told off".

Penny took charge. She was the station's most experienced diver and had completed her advanced instructor training. Sam looked apprehensively at the scuba kit laid out in front of him. He was a competent diver but he never felt truly comfortable under the water. As the child of a fisherman he was well aware of the dangers of the sea and much preferred to keep his head above the waves. Penny was already checking over the equipment. "Come on. We haven't got all day" she admonished. "Seeing as you can't be persuaded to take the advanced test we are only here to clock up some more time in your diving log and run through some basic drills. Steele wants us back before lunch". "You know diving isn't really my thing Penny. I'll keep up the standard needed for me to do rescues but I've got no interest in taking it further. You might be part-mermaid but if I need to be out to sea I prefer to be on a boat" he replied. Although she had already made her own checks to both sets of equipment she made Sam run through the pre-dive assessment too; after all, he was being tested.

Penny and Sam changed in to wetsuits and lifted the scuba kit into Neptune. Ben was to be their pilot for the morning. As Ben skilfully navigated the boat out to sea Penny explained what she had planned. "I thought we would dive over near Pontypandy Island. The water there isn't too deep so no worries about you exceeding your depth limit. I'll assess you on the basics like water entry and then we will do some swimming and practice the underwater communication signs. You will also have to transfer a casualty into Neptune" she said, indicating Dolly, the training mannequin, kitted out in a life jacket. "There should be some decent wildlife over by the island too which gives me the chance to try this out" she said, waving the water the waterproof camera Ben had given her for her last birthday.

Neptune was nearly at the island so Penny and Sam clipped on their air tanks and adjusted their face masks. Ben anchored Neptune in a safe area and all three took note of the time so they could keep an eye on the air limits. Penny and Sam sat on the edge of Neptune. Sam rolled backwards into the water first with Penny following close behind. Sam gave Penny a thumbs-up to show that all was well. Penny gave Sam some directions to follow to check he understood the most common commands. It looked more like a game of underwater charades but each of them knew they importance of regular practice to ensure that there would be no confusion in a real emergency situation. After a few minutes Penny pointed to her camera then at some rocks, she was keen to try out her first underwater photography.

As the pair got closer to the rocks they could see a tangle of fishing debris littering the sea floor. It wasn't quite the photos she had planned to take but Penny indicated to Sam that she was going to take some snaps. She wanted to show Ben the state of the area. As coastguard he would be better placed to keep and eye on the fishing boats that came into the area and watch for those that dumped waste overboard.

After a couple of minutes of taking photos and Penny felt the pressure through her air line change. The air was still flowing but something didn't feel quite right. She checked her air level indicator but it showed three quarters of a tank remaining, exactly what she thought should be left. Penny waved to Sam, tapped her regulator to show she had a problem, then pointed up to the surface. Sam signalled his acknowledgement and watched Penny kick out for the surface. However, Penny had got closer to the old nets than either of them had realised. As she kicked out her foot got tangled in the rope webbing. She tried in vain to get free but as she tried to disentangle herself she felt her air cut out completely. Penny panicked and thrashed about. Sam saw her distress and swam over to help.

Sam reached Penny just as she blacked out. He pulled out his dive knife and began to saw through the ropes that bound her to the sea floor. The old nets were tough and it felt like an eternity before the last fibres gave in to the sharp blade. Sam pulled Penny free, acutely aware that every second counted. It was a small mercy that they were only diving in shallow water and Sam could rise as fast as possible without having to worry about decompression sickness. He headed up to the light and air of the surface, towing Penny's unconscious form with him and being careful to avoid getting tangled himself.

Sam and Penny broke the surface and Sam blew on the whistle that that was attached to his wetsuit. The shrill blast shook Ben from a daydream. He looked around for the source of the sound and knew in an instant that something was wrong. His friends had surfaced far sooner than expected and the way Penny was laying in the water, supported by Sam, sent a chill to his core.

Ben manoeuvred Neptune closer to the pair in the water. He helped Sam to transfer Penny into the boat then hauled Sam in after. Sam tore off his and Penny's masks and regulators and started CPR. She looked so small and limp on the floor of the boat that the two men, friend and lover, feared the worst.

Sam continued CPR while Ben turned for shore and opened Neptune's throttle. Ben grabbed the radio. "Tom!" he shouted into transmitter, all radio protocol forgotten in his panic. "Tom, can you hear me!". A moment later the radio crackled a response "This is Mountain Rescue, go ahead Coastguard". "Tom, bring Wallaby 2 over to the Ocean Rescue, it's Penny". "Copy that Coastguard, arrival in 4 minutes".

As the boat and her crew moored at the Ocean Rescue Centre the rotors of Wallaby 2 could already be heard in the sky over Pontypandy. Tom brought the helicopter in to land. Nurse Flood was already in the rear of the helicopter. She had been up at the Mountain Rescue Centre replenishing the first aid kit when the call came in so had travelled down with Tom in case she was needed. She and Tom ran over with a stretcher and helped Ben to transfer Penny to dry land and into the back of Wallaby 2.

Sam stood in Neptune staring up at Wallaby 2 as it headed off to Newtown hospital. The sight of Ben cutting off Penny's wetsuit while Nurse Flood charged the on-board defibrillator burned into him leaving a memory that he knew would haunt him forever.