Coastal Motor Boats (CMBs) were developed by Thorneycrofts at Platt’s Eyot and introduced into the Royal Navy during World War 1. They had a shallow draft and high speed: 35knots, and were designed to slip into enemy harbours, fire off one or two torpedoes and make a quick getaway. In essence they were the early equivalents of the inflatables used today by the Royal Navy and the Marines.

They were used in the 1917 Zeebrugge action but one, CMB4, earned its fame for its involvement in the British naval action in the Baltic in 1919. This was against the Russian ‘revolutionaries’, and it contributed significantly to the independence of the three Baltic states, Estonia, Latvia and Lithuania.

Coastal Motor Boats (CMBs) were to be used to ferry British agents back and forth from Bolshevik Russia. The shallow draught and high speed of the CMB made it ideal for landing on enemy occupied shores and making a quick getaway. Augustus Agar was captain of one of these boats (CMB4) and during this time he was technically under the command of the Foreign Office.

Agar set up a small base at Terijoki just inside Finland, close to the Soviet frontier. From here he undertook secret missions to drop off and retrieve British agents on the coast of the Bay of Petrograd. To do this, his boats had to cross Bolshevik minefields and pass by a number of forts and ships guarding the entrance to the Bolshevik naval base at Kronstadt and to Petrograd, now St. Petersburg.

Also operating in the eastern Baltic Sea was a Royal Navy detachment of light cruisers and destroyers under Admiral Sir Walter Cowan. Though technically not connected, Agar regularly reported to Cowan and received assistance from him. Cowan’s mission was to keep the sea lanes open to the new republics of Finland, Latvia, Estonia and Lithuania which were under threat of being overrun by Soviet Russia.

On their missions Agar and his crews dressed in civilian clothes, to maintain the fiction that Britain was not involved. They had a uniform on board in case they were in danger of capture. Without the uniform, they could be shot as spies, though it probably would not have made much difference to the Cheka, the Bolshevik secret police.

Agar felt that his small force should be doing more than acting as a shuttle service. The Bolsheviks had seized much of the Russian fleet at Kronstadt, and Agar considered these vessels a menace to British operations and took it upon himself to attack the enemy battleships.

He set out with his two boats, HM Coastal Motor Boat 4 and another, on 17 June 1919. One had to turn back before completing its mission but Agar continued into the bay. The (‘MB4 penetrated a destroyer screen and was closing on a larger warship further inshore when the CMB4, whose hull had been damaged by gunfire, broke down. She had to be taken alongside a breakwater for repairs. They then had a terrifying twenty minutes while they had to reload the firing pistol on their torpedo, which had been accidentally discharged. They were in full view of the enemy and could have been spotted at any moment but the Soviet look-outs were not too alert.
The attack was then resumed and a Russian cruiser, the 6,645 ton Oleg was sunk, after which Lieutenant Agar retired to the safety of the open bay under heavy fire. For this he was awarded the Victoria Cross and was promoted to Lieutenant Commander on 30 June 1919.

He wrote later: ‘I throttled down to slow and crept ahead as we passed close to two destroyers. I could see black hulls and waited for the gun flashes. We were a “dead sitter” but, luckily for us, remained unseen’

‘Finally the job was done though the waiting seemed endless and nerve-wracking. Again I put on more speed and we were soon through the screen and in position. I fired our torpedo at the Oleg as if it were an ordinary practice run. I turned and made my way towards the Estonian coast hoping to mislead the enemy as to where we had come from. Within a minute there was a thick column of smoke from the Oleg. Flashes came from all directions, the forts, the destroyers and the ship itself, which were followed by splashes as the shells threw up columns of water soaking us to the skin. We were not far from Krasnaya Gorka when we turned north towards the Finnish shore at 35 knots. The whole operation had occupied less than four hours.’

The Oleg sank in twelve minutes, albeit with the relatively small loss of only five of her crew. Two days later Lt Agar was flown over the area and was delighted to see her lying on her side. He was awarded the Victoria Cross. Hampshier was awarded the DSO and Beeley the Conspicuous Gallantry Medal.

After the action CMB4 was brought back to Britain where she was shown for a while at the Imperial War museum and then returned to her makers who put her on display at Platt’s Eyot. When their works there closed she was passed back to the War Museum. She is currently on display at Duxford.

The information was almost entirely obtained from the following websites:

(1) www.twickenham-museum.org.uk, Twickenham Museum Website —Rodney M. Bennett
(2) www.wikipedia.org/wiki/Augustus_Agar