On 28 March, the Greek Central Macedonia Army Section—comprising the 12th and 20th Infantry Divisions—were put under the command of General Wilson, who established his headquarters to the north-west of Larissa. The New Zealand division took position north of Mount Olympus, while the Australian division blocked the Haliacmon valley up to the Vermion range. The RAF continued to operate from airfields in Central and Southern Greece, but few planes could be diverted to the theatre. The British forces were near to fully motorised, but their equipment was more suited to desert warfare than to Greece's steep mountain roads. They were short of tanks and anti-aircraft guns and the lines of communication across the Mediterranean were vulnerable, because each convoy had to pass close to Axis-held islands in the Aegean; despite the British Royal Navy's domination of the Aegean Sea. These logistical problems were aggravated by the limited availability of shipping and Greek port capacity.