Marine Systems Specialists
Serving the Cruising Community
In Boot Key Harbor

Independence on the Water

We specialize in off-grid systems for cruising boats. Our team is made up entirely of full time off-grid liveaboards and cruisers based in Boot Key Harbor in Marathon, FL. We rely day in and day out on the same systems we sell and install; from high-efficiency solar arrays, to lithium battery technology, to watermakers. This gives our team unique insight into the needs of self-sufficient cruising boats, their crews,  and the equipment they rely on. Sea Tek marine is about  independence on the water; for boaters, by boaters.

Our Commitment


We only sell products and equipment that we know our customers can rely on. Most of the equipment we sell is also installed on our own boats. We rely on those systems every day, and you can too. We understand that cruising boats regularly travel to remote locations where parts and service just aren’t available…isn’t that the whole point?!


We don’t offer “one-size-fits-all” solutions. The truth is; every boat, crew, and cruising budget is different. We’ll work with you to design the system that makes sense for your boat and your budget; whether it’s a complete 2000W Solar array with Lithium house batteries or a new charge controller to squeeze the most efficiency out of older solar panels.


We know that cruising doesn’t happen on a banker’s schedule, and we do our best to accommodate you. We regularly schedule work on weekends and nights to meet our customers’ needs.

We also come to your boat wherever you are. We don’t require our customers to come to the dock for us, we’ll come by water anywhere in the Marathon area.

Our Specialties

Solar Energy
 High-efficiency solar arrays and charge controllers to power your cruising lifestyle. From mounting solutions to integration with existing systems, we have the experience and expertise to bring your solar upgrade from concept to completion.
Lithium Battery Technology
Advanced Lithium Iron Phosphate house batteries offer superior performance and longevity in a fraction of the weight and space of Lead Acid batteries.
Spectra Watermakers
SeaTek is the exclusive dealer of Spectra watermakers in the Florida Keys.
Spectra - The World's Most Efficient Watermaker™

What They Say

As a result of Alex’s expert work and guidance, the quality and comfort of cruising life on my sailboat improved dramatically. I’m so glad to have met Alex and am very appreciative of all he’s done to help me out. He is SUPER customer oriented and is driven to always provide outstanding services. In fact, as he’s working on your boat, he will always point out opportunities for improvement, which always proves to be spot on. Everything Alex installed on my boat has been top notch, and I couldn’t be happier with the results. Thank you Alex!!!
Alex Miller is the owner of Sea Tek Marine in Marathon, FL "Three things particularly impressed me about Alex: first, the work was high quality, second his estimate and the final bill were the same and seemed reasonable to us and third, even knowing that we were possibly going to have power issues, he did not pressure us to buy more solar panels, and in fact encouraged us not to add any more power (batteries, solar panels or wind generator) to the boat until we really knew what we needed."  
High performance catamaran contracted Sea Tek Marine for lithium battery upgrade. "SeaTek facilitated a major lifestyle change & improvement of our cruising/liveaboard life. Alex and his team listened to our needs, considered our budget, and made perfect recommendation while keeping in mind our unique constraints of space & weight on our high performance catamaran. The installed lithium bank, it reduced the weight in our sterns by 305 lbs, raising our waterline by inches."

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