'Pineapple' (i) was a British tactical manoeuvre for use when a U-boat attack was delivered at night against a convoy from a position ahead of it (1942/45).

Created under the supervision of Captain G. Roberts of the Western Approaches Tactical Unit, the tactic usually involved some of the escorts accelerating to get ahead of the convoy, firing star shells and illuminating the area so that the U-boat felt it prudent to submerge. This allowed the convoy to evade the attacker without interception, and after 15 minutes the escorts reversed course to rejoin the convoy, this time not firing star shells and in the process also undertaking a sonar sweep of the submerged and therefore slow U-boat, which might therefore be taken unawares and therefore back on the surface, and then be attacked with gun fire and then depth charges if required.