By Guy Taylor Simon Tucker is no stranger to life-threatening predicaments. Chatting from his offices in sleepy Bath, the boss of the maritime surveillance firm SRT Systems recalls an incident while working in Mexico. Held up by local police with guns pressed against his back, Tucker looked left and saw his taxi driver make a bolt for it down a nearby alley. “Everyone was speaking Spanish,” he said. “I don’t speak a word, and I was thinking, right, what’s gonna happen?” “If I hear he gets shot first, I’m gonna leg it that way because then the car is between me and whoever’s shooting, and I hop…