The sole Ju 88 E-0 was modified with another MG 131 firing rearward just below the turret, one firing forward through the nose and twin MG 81Z machine guns in the integrated ventral "Bola" gondola firing rearward. Two other airframes had their engines and outer wings removed to act as testbeds for water ditching, as it was planned to use the Ju 188 in long overwater flights against British shipping. A second Ju 188 test airframe was built from another Ju 88 A-4, this one including a larger, more trapezoidal vertical tail surface set to provide more directional control at higher altitudes, a feature also used on future Ju 88 models, most importantly on the Ju 88G night fighters. Originally known as Ju 88 V44, this airframe was later named Ju 188 V1.