Joseph M. Markman, aka the Milfoil King, is the founder and president of Lake Defense Force.

He grew up in a Madrona neighborhood home overlooking Lake Washington, and spent hundreds of hours as a teen training and racing on the water with the Mt. Baker Rowing Center.

He became a certified scuba diver at 12 years old, and later a high school student in 2008 he learned how to turn his hobby into a summer job when a friend showed him how to remove milfoil from waterfront properties on Mercer Island.

Joe went to the University of Colorado to study business and real estate, but returned home each summer to run his growing milfoil removal firm and learn more about Northwest lakes’ plants and animals. After college, Joe worked in many facets of multifamily and corporate real estate for a few years, but ultimately made the leap to run his Milfoil King business full time in 2018. In 2020, he changed the name of his firm to Lake Defense Force to highlight its broader mandate to provide an array of shoreline health, maintenance and construction services.

Meet Our Team


Dive Team Lead

Job Description

The Dive Team Lead is in charge of setting goals and tasks for one to two underwater landscaping jobs per day, and leading a four-person team to accomplish them. Teams consist of the lead, another diver and two surface support specialists. The lead is responsible for providing efficient, clean complete service at each job as well as respectful interaction with customers.

Dive Tech

Job Description

Dive Techs are responsible for working at the direction of Dive Leads in four-person teams to accomplish our waterfront restoration work. Dive Techs will dive for two to six hours per day at depths of around 10 feet to remove milfoil and other invasive species from their roots in lake floors. Teams consist of two divers and two dive tenders, who provide surface support. While job duties are shared, dive techs take pride in providing efficient, clean, quality service.

Sales Associate

Job Description

Milfoil King salespeople are responsible for generating sales of our service and managing the sales process. You will be the first person our client makes contact with. Your voice, demeanor, attitude and familiarity with all aspects of lake management set the bar of expectations from our clients. You will need to exude trust, knowledge and a deep understanding waterfront maintenance. The salesperson will be responsible for the full customer experience.

Dive Tender

Job Description

The Dive Tender is responsible for the above-surface work, including the gathering of milfoil cut loose by divers, putting it into bags, and taking it to waste disposal sites. Tenders are key members of four-person teams that work together at one to two sites per day. Tenders are the most visible members of every team and are responsible for answering questions from customers and new prospects as well as monitoring the safety of divers.