▁a ▁ste amer ▁of ▁. ▁Ell isp ont os ▁was ▁en ▁route ▁to ▁Monte video ▁from ▁Amsterdam ▁when ▁s unk ▁by ▁G ross ▁and ▁U B - 4 ▁on ▁ 1 7 ▁April . ▁Although ▁German ▁U - bo ats ▁s ank ▁over ▁ 1 0 0 , 0 0 0 ▁tons ▁of ▁sh ipping ▁in ▁each ▁of ▁May ▁and ▁June , ▁U B - 4 ▁did ▁not ▁contribute ▁to ▁those ▁tot als . ▁She ▁did ▁add ▁one ▁ship ▁to ▁the ▁ 9 8 , 0 0 0 - ton ▁t ally ▁for ▁July ▁when ▁she ▁s ank ▁the ▁Belg ian ▁ship ▁Prin ces se ▁Marie ▁Jose ▁and ▁her ▁load ▁of ▁coal ▁on ▁ 2 9 ▁July . ▁The ▁ 1 , 9 5 4 - ton ▁ste amer ▁had ▁sa iled ▁from ▁D unst on ▁and ▁was ▁head ed ▁to ▁Bor de aux ▁when ▁s unk ▁ ▁from ▁the ▁Sh ip w ash ▁Light ship ▁off ▁Har wich . ▁ ▁S inking ▁▁ ▁On ▁ 1 4 ▁August , ▁the ▁ 5 9 - ton ▁British ▁fish ing ▁sm ack ▁B ona ▁F ide ▁was ▁stopped ▁by ▁a ▁U - bo at , ▁board ed , ▁and ▁s unk ▁with ▁explos ives ▁ ▁east - n ortheast ▁of ▁Low esto ft . ▁According ▁to ▁the ▁website ▁U bo at . net , ▁this ▁attack ▁was ▁likely ▁by ▁U B - 4 , ▁because ▁she ▁was ▁operating ▁in ▁the ▁area ▁on ▁her ▁four teenth ▁pat rol . ▁Reg ard less ▁of ▁the ▁identity