MOST SECRET ANNEX Director of Plans, Admiralty. With reference to your note dated 15th July, 1942, the following is an estimate prepared by the Joint Intelligence staff of Naval and Air scales of attack on ports overseas which fall within the ambit of operation "ROUND-UP". 2. NAVAL It is considered that scales of attack for any of the ports mentioned will be as follows:(i) Attack by light surface craft (Destroyers, T.B's, and E-boats). (ii) Minelaying by aircraft, light surface craft and submarines.