As we clambered down the cliff in the dying light, the grim reality of our situation was revealed. A wild rocky coast, a dark cloudy night with a rising wind. We were alone. We were hungry. The desperate fight for survival was on, in the wilds of … well, North Yorkshire actually.

OK, so we could have trekked to a chip shop. And when we got to our destination – an old beach cabin owned by a local fisherman, Sean Baxter – we discovered that inside he had left a big hand-written sign, saying, "Eat Me!", with an arrow pointing to the sink. In it was a live lobster. On the table was a bowl of potato salad. My fellow-survivalist Fred took it outside. "I'm not going to cheat. We are here to survive, not to live on Sean's largesse."

"What about the lobster?"

Fred grinned craftily. "How on earth did he crawl into that sink? Let's eat."

My original idea had been simple. I wanted to walk out of my front door with wilderness gear on my back and survive on foraged foods, maybe in the local woods. Only when I analysed the idea, it began to fall apart. Wild camping is illegal in England and Wales. And is gathering wild food strictly legal? I didn't know.

My thoughts swung to the coast – would that be easier? After all, sea fishing is licence-free without restrictions. Or is it? A phone call to Sean, who owns a fishing cabin in Staithes, near Whitby, soon put me right."Well, most fish have size limits. Cod, for example, has to be 35cm long to be legally landed."

Investigation soon revealed a mass of legislation. Some species are specially protected; some sites are guarded; some ancient rights of foraging are curtailed. The rules and restrictions were intended, I had to admit, to ensure the survival of the wild flora and fauna in question, but what about me? What about my deep desire to live close to nature?

So it was that the plan emerged: I would attempt to survive, but within the law. My own long-term survival, after all, was inextricably linked to the survival of all edible food species. My friend, Fred, a naturalist himself, would ensure they were observed.

The lobster in our cabin measured 87mm from the rear of its eye socket to the edge of its main carapace. Edible size. I knew this because by now I had a Limited Shellfish Permit. With it had come a useful size chart.

Sean had left instructions. Boil large pan of water. Drop lobster in. Wait 10 minutes. Remove and eat. We did so.

"That is the best lobster I've ever tasted," was Fred's opinion. "I hope we can catch one of our own."

Our hopes lay in two lobster pots, two fishing rods, and a copy of the tide tables. It seemed straightforward: low water is at 12.34am. Our first attempt to lay a pot would be in the dark.

We spent the next few hours tying ropes and licence tags to pots. For bait we'd brought a bag of frozen squid from a Chinese supermarket. Yes, it would have been easier to just cook and eat the squid, but that was not our game. At midnight we headed out. Fortunately I had a big hand torch; headtorches don't reveal much. It was pitch dark as we stumbled among huge boulders covered in weed, pools thick with bladderwrack and deep gullies choked in kelp. Gullies make good lobster territory, but also excellent man traps. We both disappeared up to our waists, skinning shins and bashing toes.

The law when it comes to seashore foraging is something like a mass of sharp rocks just below the water. We were on the foreshore, the area of land uncovered at low tide. In England that land is owned by the Crown Estate, the National Trust and various private bodies. Tread carefully then. What about our quarry? The right to fish for shellfish and crustacea is enshrined in common law, but around it, like tricky sea mists, is a miasma of bylaws. Check with your regional Sea Fisheries Committee.

Just above the low water mark we found what we were searching for: a big boulder over a neat little cave. The squid went into the bait bag, a few bits into the pot itself. Then we wedged the pot under the boulder and tied it on.

An hour later we were back at the shed, sipping dark rum around a campfire of foraged beach timber. "Early autumn," Sean had told us, "is when the mackerel are moving, but the sea trout and bass are still around. Try a lure on the incoming tide."

At three we curled up in sleeping bags, swearing we would be up at six for that incoming tide. We made it by about eight, as the water was visibly turning. Fred broke his lightweight river rod using a hefty sea spinner. I lost my lure in weed on the fifth cast. By then the retreating tide was revealing rocks and pools, so we abandoned the rods and went hunting shellfish, gathering winkles and crabs and, later on, our lost fishing tackle.

We were getting hungry. We needed to get back to our pots. This was exciting. A lobster lunch – the licence allows two per day. When we reached the pots, however, the first was disappointingly empty. The second felt heavier and as I got it clear, I could see there was something there – but what?

"Eels?"

Fred studied the two slimy bronze creatures about as long as my hand. "Not eels. I think they are rockling."

"Edible?"

"In the circumstances – yes."

We re-baited and set the pots. Back at the hut we found a bit of flour in a tin so made chapatis and fried the rockling. They tasted oily but delicious – in the circumstances.

That evening our fishing had a slightly manic feel to it. Fish could be seen swirling on the surface. At one point a sea bass as long as my forearm leapt out of the water a few feet away. I swear it was grinning. We couldn't catch anything. Fred went off and relocated the potato salad. We fried it up. It was delicious.

Exhausted after our largely fruitless exertions, we crawled into our sleeping bags, setting the alarm for soon after midnight so we could check our pots. But when we rounded the headland and shone the torch out to where our pots should be, there was a surprise waiting for us. Water.

"That's not right!" I checked my watch. Only 10 minutes to low water. Then we noticed the other information on the chart, telling us how big each tide was. Every 24 hours low tide moves forward by about 48 minutes, but the tides also change in height and depth. This tide was going out 40cm less than the previous one. So our pots were under water and – oh dear – we hadn't marked them with a buoy.

At that moment we both felt the swell of panic and chaos. No breakfast. Lost pots. We sploshed around for a while before realising how pointless it was in the darkness.

Twelve hours later, we were back in daylight, swimming around in cold seawater to retrieved the pots. And this time there was success: two lobsters, one large enough to keep. Back on dry land we gazed at the creature in awe, so beautiful, so colourful – so tempting to eat it raw there and then.

After a lobster lunch, we fished. Our luck had turned: a brace of good-sized mackerel well over the 30cm limit, velvet crabs and two more lobsters, one of edible size.

Now we were successful, everything changed. We were at one with the tides and the moon, alert to the movement of birds and changes in wind and cloud. We never left without the right equipment or came back empty-handed. I had got what I wanted – that feeling of connection with nature. And we hadn't broken anything, no rules or regulations – just one fishing rod.