Quality of effort was the basis of Dowding's worst fears: not simply pilot training, or even experience, but also the loss of quality that fatigue would bring. There was a formal demand from the Admiralty (via the Air Ministry) that Dowding must fly standing patrols over the convoys; and this was the very thing that radar was designed to obviate. Dowding compromised. But even so, there were many July days when Fighter Command put up as many as 600 sorties. The strain on the pilots and the maintenance crews was terrific but there could be no question of a general rotation of squadrons yet, even if those in the quieter sectors had been up to operational standards. And they weren't.

Dowding's pilots, maintenance crews, and support organizations could not keep up this pace for a prolonged period and then fight a major battle. The Luftwaffe, on the other hand, could afford this loss ratio, if at the end of it Fighter Command ceased to exist. Meanwhile, the Air Fleets were able to arrange their flying schedules as they chose but Fighter Command was forced to put its standing patrols up every day.

By now, eighteen ships and four RN destroyers had been sunk. In daylight, the Straits had become so dangerous that destroyers had been withdrawn from Dover. Instead of transferring the coal to the railways, the Admiralty decided it would be enough to schedule the coastal convoys so that they reached the Dover Straits as darkness fell. The first such convoy, CW9, was assembled at Southend. The masters of some two dozen colliers were gathered in the dance-hall on Southend pier and addressed by an RNR Commander. He told these men — who were now sailing under Admiralty orders because their ships had been requisitioned — that German radio propaganda was claiming to have closed the channel. "We don't give a damn for your coal," he said. "We'd send you through empty if we had to. It's a matter of prestige." Leaving the Thames on the evening tide of 7 August, with nine RN escorts including two destroyers, with fully manned anti-aircraft guns and cable balloons, convoy CW9 set sail.

The Germans had set up one of their Freya radar sets on the cliffs at Wissant, opposite Folkestone. They used it for locating shipping, and had ample warning of the convoy's approach. As dawn came, German torpedo boats attacked out of the half-light. They sank three ships and damaged three others.

Fliegerkorps VIU, commanded by General Wolfram von Richthofen, a dive-bomber specialist, was chosen to mount most of this day's attacks upon the convoy. The cloud base that morning was a little over 2,000 feet: there was not much head room for dive-bombing, especially since there were cable balloons on the ships. Park committed about five squadrons. In spite of their fighter escort, The Ju 87s, arriving in small relays, found it almost impossible to get a clear bombing dive at the target.

At midday the Luftwaffe tried a different tactic: about thirty Bf 109s of JG 27, and some Bf 110s, flew escort for three Geschwader of Ju 87s.

The Ventnor, Isle of Wight, radar found an unusually clear blip on the cathode-ray tube. The clarity was due to the size of this formation of aircraft. The Sector Controller fed over thirty Hurricanes and Spitfires into the air above the convoy. The battle began, and JG 27 skilfully engaged the British fighters, leaving the Stukas free to bomb. The accuracy of the dive bomber was forcibly demonstrated in the next ten minutes, as four merchant ships were sunk and seven were badly damaged. As the attack continued, the ships scattered, so dispersing the protection of the balloon barrage.

Determined to destroy every ship in the convoy, von Richthofen's Fliegerkorps VIII mounted another attack that afternoon as the convoy was trying to reassemble off the Isle of Wight. Eighty-two Ju 87s, and almost as many fighters, took part in the attack. Again they ran into RAF fighters vectored by very accurate plots from the radar chain.

By the end of the day the convoy was shattered: loose cargo, such as coal, produces progressive list in rough water and can easily capsize such vessels. Six ships limped into their nearest port. Of the twenty merchant ships that had originally set out for Swanage, Dorset, only four got there.

And for the men who survived cannon shell, burning fuel, or disintegrating aeroplanes, there was no succour in the sea. At Bembridge, Isle of Wight, the lifeboat Jesse Lumb was launched at 5:45 p.m. into what was recorded as "a strong south-west wind and very rough sea." They reached a place around which a plane was circling, to find, not airmen, but an RAF power boat that had been machine-gunned and was now flying a distress signal.

Fighter Command, a force designed specifically to defend Britain's coastline, had no proper air-sea rescue organization. Now there were a mere eighteen motor boats trying to provide a rescue service along the entire south coast. Or were they only providing some kind of bogus reassurance to the flyers?

The German air force provided their crews with a proper air-sea rescue organization. The key to this was the float planes that were able both to search and rescue. And the Luftwaffe gave their flyers flares and sea dye, yellow skullcaps, and one-man dinghies that enabled a fighter pilot to get out of the sea. Even in summer, British waters are cold. Immersed in them, with only a 'Mae West' life jacket that had to be inflated from the lungs of exhausted or injured men, many RAF flyers died in sight of England's beaches. Even in summer temperatures, few men remained conscious after two hours in the sea.

During this month there were no more such 'prestige' coal convoys through the Channel. Those same men in the Admiralty, supported by their Air Ministry counterparts, who had pressured Dowding to fly standing patrols over the domestic shipping now discovered that these cargoes could be moved by rail. Had this discovery come a few weeks earlier, many RAF pilots including a high proportion of flight commanders and experienced Regular officers would have still been alive. In just three weeks of July, no less than 220 RAF flyers had been lost in the sea. Also, there were the injured and dead sailors.

But in Britain this day was one of rejoicing. The Air Ministry mathematicians kept to their usual routine of giving the true figures of RAF losses while accepting without question the wild claims of the RAF pilots. They announced that sixty German aircraft had been destroyed. People who knew that the pilots were being too optimistic kept the opinion to themselves. In any case, the true figures (thirty-one German aircraft shot down, for the loss of nineteen RAF fighters) were praiseworthy. The Nazi propaganda service announced that forty-nine RAF fighters had been shot down: and the Germans also celebrated. They had done great destruction to the ships and the Kanalkampf-führer task was fulfilled, even if the original battle-group he had been given had proved inadequate.

The extremely poor intelligence estimates upon which the Luftwaffe High Command depended had overestimated the fighter strength of the RAF but it had badly underestimated the rate of manufacture. The restraint that Dowding showed, as he committed only small numbers of aircraft, the lack of RAF fighter pilots for interrogation, and the sort of reports that Luftwaffe air crews brought back from the Battle: all these factors encouraged the Luftwaffe High Command to believe that Fighter Command had very small resources left. In this context, the comparatively large air battles of 8 August (in which a couple of hundred aircraft fought) were interpreted by German intelligence as Fighter Command's last desperate fling.

If the Luftwaffe's view of the RAF was sanguine, the RAF was shedding some of its fears of the Luftwaffe. The day's air fighting had shown the Ju 87 a most vulnerable adversary, while the Hurricanes had proved good enough to account for nine out of ten of the destroyed Bf 109s.