George spent £527,287.60 to buy 1,318,219 shares priced at 40 pence, according to a market disclosure by Benchmark.
Chief financial officer Septima Maguire bought 250,000 shares for £100,000, and non-executive director Yngve Myhre spent £80,000 on 200,000 shares. Myhre is a former chief executive of Norwegian salmon farmer SalMar and current boss on Nova Austral, a US/Norwegian owned salmon farmer in the far south of Chile.
Three other non-executive directors – Susan Searle (100,000 shares), Hugo Wahnish (75,000) and Kevin Quinn (25,000) - also bought shares in the offer, as did chief scientific officer Alex Raeber (7,658).
In total, the directors and Raeber, who are all classed as persons discharging managerial responsibilities, invested £790,350.80.
The share offer raised £43 million for Benchmark, which intends to spend £19m scaling up its CleanTreat water treatment system in preparation for the roll-out of its BMK08 sea lice treatment once that wins permission for use from regulatory authorities.