The dagger board scrunched on the gravel of the river bottom. 'Pull it up!' I yelled at James, and although he obeyed at once, it still wasn't quite quick enough. Meanwhile I hauled the mainsheet and luffed the old Mirror in an attempt to find the deeper water, but we were too late. In what seemed only a second or two, we were hard aground, although we still appeared to be in the middle of the river.

'Another fine mess you've got me into Olly', I told him.

'No' he reminded me, 'I'm Stanley, You're Olly, remember? - the fat one,' he added, somewhat cruelly, I thought. But this was my nephew's latest game, and we played it as we went along to prevent him becoming bored. Not that there really was a chance of it. James loves sailing, so much so that his parents had let him come away on a camping weekend in the old Mirror. I rolled up my trousers and went over the side, anchor in hand. After splashing upstream a little, I dug it in and returned to make the end fast aboard. 'We may as well eat while we wait for the tide to make a little,' I said and James got the lunch box out of the locker.

It had been a grand morning, with a light southerly breeze when we'd launched off the beach south of Harwich. We'd headed north up into the Stour, a river I hadn't been up for years. On the last occasion it'd been at the wheel of a spritsail Barge in a stiffish breeze, with more to watch than the scenery. Even so, I'd realised it was beautiful and was looking forward to this weekend. We'd sailed round rusting cargo ships laid up in the entrance, and across to Shotley on the north side, keeping well clear of the Ferry traffic. The wind had backed round to the east and had blown us gently up river, where we'd hugged the northern shore and run along in the shallows to cheat the last of the ebb. Low water was about noon and I didn't think we'd get very far up the river, but you never know in a dinghy of course. I had been about to suggest we head towards the southern shore where the main channel lay when James had spoken.

'What's that, Uncle?'

I looked under the sail to where he was pointing. A chill ran down my spine before reason took over. It looked for all the world like white water of the kind canoeists love to shoot, but I knew there was nothing like this on the Stour. This was Constable country, where gentle streams trickled through the wheels of haywains, after all. But what could it be? We'd decided to investigate, even though it meant the risk of grounding. No harm could come to us in this weather after all, and we'd no tight schedule to keep. Just as well, as we had to spend an hour at anchor as a result. So we ate and basked in the noonday sun until the young flood floated us to the hook and we peered into the distance trying to make out what the mass of white could be. Eventually, when I thought there should be enough water, we got under way again. James took the helm for a moment whilst I got in the anchor. Then we changed places and squared away before the breeze.

'Swans!' James exclaimed from his vantage point on the starboard side. 'A whole load of them'.

So that's what our white mass was! And presently, my eyes could make them out too. I've always thought of swans as lonely creatures living in pairs, but at Strutton Ness there was a great colony of them, and every pair of black beady eyes followed us as we ghosted past.

The mystery solved, I said we should find the main channel. It would be quite narrow and we'd have to beat back against the flood, so we headed the old Mirror over to the south. No sooner had we done so than we grounded. We pushed off with an oar and found some deeper water, but in next to no time we bumped again. We tried clawing our way back, but without success. My oft-repeated claim that a Mirror will go to windward on a wet flannel was proved untrue. Instead we bumped and dragged our way across the river towards Mistley.

'There's deep water over there somewhere!' I told James, pointing to where cargo ships were tied up against the quay. But we were past them before we found it and then realised just how fast the flood was sluicing through. I began wondering whether we could make against it in such a light breeze. 'Another fine mess you've got me into Stanley', I quipped, and James laughed. 'We've got our work cut out for a bit,' I added.

Crouching down in the bottom of the boat to lessen the wind turbulence, we pointed the old Mirror as high as she'd go. When it seemed as if we must hit one of the ships, we went about, over to the exposed mud on the other side of the narrow channel. Back and forth we tacked, making a few feet at a time. I looked at my watch. It was two o'clock. Gradually we passed first one then another of the ships. James did his drill with the jib like an old hand, and had it drawing in a flash. Presently we closed the first of the buoys marking the channel and decided to stick to it. It took us until 4pm to fetch Wrabness, a distance of only 2½ miles. As we pushed on, the wind rose a little enabling us to get out of our cramped positions and onto the side decks. By Erwarton Ness, it had freshened enough to make the spray fly and we put on our waterproofs. The sun started to lose its power and we grew colder. 'How much longer, Uncle?' James asked, looking a little blue.

'Once we're round Shotley Point, over there.' I replied, 'It'll be easy. The wind'll be abeam all the way up the Orwell. Can you hang on?' He nodded and I fancied his teeth chattered a little, but then he grinned, 'Another fine mess you've got me into Olly'.

'Oh shut up', I answered with mock severity in my voice. 'Have a biscuit, and keep an eye on that Ferry coming in.'

There was no danger from it, of course, as we were well over to the north side of the river, but it helped to keep his mind occupied. It was six o'clock before we rounded Shotley Point and bore away up the Orwell. I'd been feeling a little guilty at subjecting him to that long beat and had even toyed with the idea of putting back, grounding near Wrabness and getting the train back to the car at Harwich. But I knew he would have been bitterly disappointed if we had done so, once the immediate discomfort had worn off. And I was right. When we turned north, the wind on our beam lifted us onto an occasional plane and we sped along aided by the last of the flood up the Orwell. The cold left James in the elation of fast sailing and it was just about high water when we beached the old Mirror a little way east of Pin Mill. I'd been there before without the boat and had earmarked the spot as a reasonable camp. The small tent came out of the locker and our insulating mats and sleeping bags from the side tanks. Our clothes were in the stern tank and we changed into dry gear with a couple of extra sweaters. It was getting cold as it grew darker. James assembled the stove for me and we soon had some hot food. Before turning in, I walked a very tired nephew along to the village to telephone his mother.

'I'm not in Davy Jones's locker!' he assured her proudly, sounding as bright as a new brass button.

But back in the tent he was asleep almost before I switched off the torch. 'Good night, Stanley', I said. 'Good night Olly,' he mumbled from the warm depth of his sleeping bag.

He stirred for the first time as I got up to put some water on to boil next morning about 7.30. The wind had come round to the west in the night and was still light. Several craft were already underway on the early ebb and it looked another fine day. We sat on a tuft of grass and ate our cereal, drank tea and polished off a couple of hard boiled eggs before we started to pack.

'Can we go up the river as far as Ipswich?' James asked, studying the chart.

'We'll try, but the wind's a little light, and the tide's already ebbing'.

We blew up the inflatable beach rollers, pushed the old Mirror down to the water's edge and loaded the gear aboard. We were ready just before nine, hauled up the sails and set about threading our way through the moored yachts. The eastern side of the Orwell is far prettier than the west, and we headed the old Mirror over. The charts showed a lot of mud exposed at low water and I knew we'd have to be careful trying to cheat the ebb in the shallows on our way up river.

'Do you know why the old sailors call their rum ration "grog"?' I asked as we sailed along. James didn't, so I explained. 'Over there – in Nacton – lived Admiral Vernon who was known to his sailors as "Old Grog", because he used to wear a cloak made from a material called Grogram. And it was he who first watered down the Navy's rum in the way it still is today. The sailors didn't like it of course, and the rum and water mixture soon became known as "old Grog's mixture", and then just simply as "Grog". And that name's stuck ever since'.

I was proud of my little bit of local knowledge, but telling it had taken my mind off sailing. The dagger board sliding into the mud brought me back to the present. 'Pull it up!' I yelled at James, whilst I luffed the old Mirror toward the deeper channel. But once again, I'd left it too late and we were aground. I got an oar over the side and tried to push her off, but she was stuck, and the Orwell was emptying fast, it seemed. Around us the mud began to break surface, all except directly astern.

'I'll have to go over the side,' I announced. But there was no time to roll up my trousers, and there was no hard gravel beneath my feet. I slipped knee-deep into the soft oozy mud. James watched as I worked my way along to the bow, holding onto the gun'l for support. The old Mirror bobbed without my weight aboard, but didn't quite float. I tried to push her astern, but at each heave, I only sank deeper. 'Take out the dagger board and pass it to me', I instructed. Laying it in the water and standing on it would help. I gave another heave. The boat moved a short way, then stopped. I'd forgotten the rudder. Its blade was now well dug in and the tiller hard over. 'Try and pull it up James', but it was too firmly stuck for him to manage. There was nothing else for it, I'd have to go myself. I found more soft patches and sank up to my bottom in mud at one point before I reached the stern. James started to laugh, but I was quite unable to see the funny side of things.

'Shut up!' I said sharply. His face took on a concerned look when he realised I wasn't playing games. 'Are we in danger, Uncle?', he asked. 'Yes', I replied, 'We could die.' I saw a horrified look cross his little face, ' . . . Of boredom!' I added. 'We won't have water to float off again for hours if we don't get her off now!'

I couldn't face the prospect of just playing Stan and Olly all day, or worse still, 'I spy...'. With that, the rudder blade came free and I began to work my way back to the bow. Once more I stood on the dagger board and heaved. This time she moved, but I had to stop at the end of my reach, get down into the mud and move the board three or four times before the old Mirror was finally afloat. By that time there wasn't much of me that wasn't covered in mud. Once I felt there was a chance of getting off, I turned to boat, picked up the daggerboard and flung it onto the foredeck. Mud on the underside of it squirted out as it landed and caught James square amidships. This time he didn't laugh. Next I tried to get back aboard. The freeboard of a Mirror always seems low when there's anything of a sea running, but viewed from the knee-deep-in-the-mud position, it seems very high indeed. But I made it, slithered upright and grabbed an oar to pole her out of the gully we'd inadvertently strayed into. Eventually, James slid the board back in, pushed it down little by little, whilst I released the rudder uphaul. Catching the mainsheet of the gently flogging sail, I pulled it in and breathed a sigh of relief as the old Mirror responded and moved forwards.

As soon as we could, we headed her over into the buoyed channel and reached back towards Pin Mill. We'd not be going to Ipswich on this trip, I explained, but James didn't look as if he would mind too much.

I looked at him and caught him eyeing me. We must have been a bizarre sight! 'Another fine mess you've got me into Stanley!' I said. James started to laugh, and kept on until the mud on his face cracked and fell off. He would of course - he's that kind of a kid.