1915年6月,佛兰德区舰队的潜艇共击沉容积逾14000总吨的商船,而UB-13号的首个受害者达尔西号(Dulcie)便几乎占了总数的七分之一。[17]这艘注册总吨位为2033吨的英国煤船于6月19日从邓斯顿(英语:Dunston, Tyne and Wear)前往勒阿弗尔,行至奧德堡以东约6海里(11公里)处遭贝克尔发射鱼雷击沉。[18]达尔西号上有1人在袭击中丧生。它也是UB-13号在6月击沉的唯一一艘船。[19]
^Helgason, Guðmundur. Ships hit during WWI: Dulcie. German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. [2009-03-17].
^ 19.019.119.219.319.4Helgason, Guðmundur. Ships hit by UB 13. German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. [2009-03-17].
^Helgason, Guðmundur. Ships hit during WWI: Iceni. German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net., Helgason, Guðmundur. Ships hit during WWI: Salacia. German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net., Helgason, Guðmundur. Ships hit during WWI: Young Percy. German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net.
^Penwith District Council. Boat Types. Penzance: Penwith District Council. 2009 [2009-03-04]. (原始内容存档于2007-05-27).
^Helgason, Guðmundur. Ships hit during WWI: Harold. German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net., Helgason, Guðmundur. Ships hit during WWI: Reliance. German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net., Helgason, Guðmundur. Ships hit during WWI: Trevose. German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net., Helgason, Guðmundur. Ships hit during WWI: Try On. German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved on 2009-03-17.
^Helgason, Guðmundur. WWI U-boat commanders: Arthur Metz. German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. [2009-03-17].
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