When Viscount Lisle was appointed Lord Admiral in January 1543, Scotland was high on the agenda. As we have seen, he was doubling as Warden General of the Marches at the time, and the active command on the north-east coast was given to Sir William Woodhouse as Admiral of the North Seas. In February Woodhouse was given command of four Newcastle ships which were taken up specifically to ‘keep the seas’ between the Humber and the Tweed, and his instructions were to take any Scottish ship and any intruding Frenchmen as ‘good prizes’. No state of war existed with either of these kingdoms, but the intention was clearly to keep up the pressure on the regency government of the earl of Arran, and to prevent the French from interfering. Whether any such prizes were taken is not clear, but it is likely that Woodhouse was there mainly as a deterrent. The diplomatic situation was delicate, and at the end of April one of Andrew Flammock's captains, serving in the Western Approaches,was reprimanded by the Council for ‘staying both friends and foes’ – the distinction presumably not being clear to him. The war with France, which eventually came at the beginning of July, was clearly intended before that, and on 15 June Sir Rhys Mansell was briefed as Admiral of a sizeable English fleet in the Channel, which included ten or eleven of the king's own ships. His instructions ordered him to take any French ship which he could find, but not to touch the Scots, who at that point were about to negotiate the treaty of Greenwich. On 20 June the king went to Harwich to view the haven in the Colne where several of his ships were then being prepared, and pronounced himself well pleased with the arrangements.

The first action of the war was fought by Mansell on 6 July, when, as he put it,‘lying in the bottom of the sea’, he spied the approach of sixteen sail of Frenchmen, and the following morning between four and five o’clock, he engaged them. After a fierce exchange of artillery fire lasting almost three hours, he endeavoured to close with the enemy, concentrating his attentions upon the Sacre, which had become detached from the others. The Sacre, however, proved elusive, as Mansell's subsequent account makes clear.