Big defence companies are acquiring maritime capabilities, with Thales agreeing to acquire a controlling stake in sea-drone maker Exail for €3.9bn. This move is part of a larger trend, with Lockheed Martin beating rivals to acquire naval tech group Ultra Maritime for $3.5bn. Italy's Fincantieri has invested €600mn in four underwater defence companies.

The market for unmanned anti-submarine warfare is expected to grow from €85bn last year to over €700bn by 2030. Exail is expected to increase revenue by a fifth a year, on average, to 2030.

The acquisition of Exail by Thales is expected to be worth some 40 times this year's operating profit, which falls to 27 times by 2027, after factoring in expected growth and cost cuts.

This trend has significant implications for investors and business leaders, as defence contractors look to offer integrated suites of capabilities to their clients, including maritime products and software.