Each school has a lineage that tells a story about its history, and Sah Doh Kuk Sul of Crystal Lake is no exception. The lead instructor and school owner of Sah Doh Kuk Sul of Crystal Lake is Pu Sa Bum Nim (PSBN) Sarah Mertens. PSBN (meaning 3rd degree black belt) Mertens began her Kuk Sul journey in 2009 at the University of Illinois at Urbana-Champaign.
While at the university, she studied under Kyo Sa Nim (KSN, 2nd degree) Brandon Beamer, before training under Sa Bum Nim (SBN, 4th degree) Gary Kloster, under whom she earned her 1st degree black belt in 2013. She then ran the UIUC school for two years as the head instructor, before moving to Austin, Texas in 2015.
While in Austin, PSBN Mertens had the pleasure of training and instructing with a large team consisting of many 1st through 6th degree black belts, all training under Joo Im Kwahn Jang Nim (JIKJN, 6th degree) Timothy King. PSBN Mertens trained in Austin for 5 years, earning her 2nd degree black belt in 2018 and participating with the Oak Hill [Austin] school at the World Kuk Sool tournament, where the Oak Hill school worked together to achieve second and first place for many years running. At Oak Hill, PSBN Mertens had the pleasure of instructing children's classes (aged 4-7), women's self defense classes, and the open adult conditioning classes.
In early 2021, PSBN Mertens moved back to Illinois. PSBN Mertens chose Crystal Lake to settle down in with her family for it's wonderful community, as well as a local Kuk Sool Won™ school. Beginning in 2007, Kuk Sul was offered at McHenry County Community College, instructed by 6th degree master JIKJN Tim Seitz, who is also a professor at the college. Unfortunately, due to Covid-19, the existing school had ceased meeting prior to PSBN Mertens' move, leading the MCC to no longer offer Kuk Sul as part of its curriculum. With the encouragement from her instructor, JIKJN Tim Seitz, as well as other Kuk Sul peers, PSBN Mertens began the process of opening a new Kuk Sul school in Crystal Lake.
In 2022, PSBN Mertens began training with Ji Do Kwahn Jahng Nim (JDKJN, 7th degree) Jeff Green monthly in Bettendorf, Iowa, under whom she received her 3rd degree black belt in August 2022. In November 2022, PSBN Mertens opened her own school, which offers a variety of classes and programs for both children and adults in Crystal Lake. PSBN Mertens is currently training under Chong Kwahn Jahng Nim Ben Mitchell, of Sah Doh Kuk Sul of Peoria. She is always looking for ways to participate and give back to the community.