Scientist David McBee plans to descend down the San Marcos River to raise awareness for one of the most biologically diverse aquatic ecosystems in the Southwest.

The San Marcos River is a spring-fed river that flows from its source, the San Marcos Springs in San Marcos, Texas 75 miles south to the Guadalupe River confluence in Gonzales County, Texas.

Its cool, clear waters offer year-round recreation such as swimming, tubing, kayaking and stand up paddleboarding. It is home to several threatened and endangered species including the Texas Blind Salamander, San Marcos Salamander, Fountain Darter, San Marcos Gambusia, and Texas Wild Rice.

The San Marcos Springs is also the starting point for the Texas Water Safari, a 262-mile source-to-sea canoe race to the Gulf of Mexico. This race is appropriately dubbed “The World’s Toughest Canoe Race.”

My friend Brian and I have chosen to attempt the first self-supported stand up paddleboard descent of the San Marcos River for a variety of reasons. First and foremost, we are both scientists; I am a Wildlife Biologist and Brian is a Hydrogeologist. The San Marcos River is one of the most biologically diverse aquatic ecosystems in the southwest United States with opportunities to observe hundreds of different species up close.

Paddling the entire river also gives a rare firsthand view of the awesome destructive and life-giving power of the river.

We hope that this trip will allow us to raise awareness of how biologically diverse and fragile the San Marcos river ecosystem is, and the many threats that the river faces, from groundwater pumping to pollution from urbanized runoff.

Our plan for the trip is to complete the entire 75-mile trip in three to four days beginning in late September or early October, depending on weather and streamflow conditions. Maintaining a pace of 18 to 25 miles per day will allow us to pack light and more easily complete the numerous dam and low water crossing portages along our route. We will rely on hammock camping in cypress and oak trees along the river as our primary sleep strategy, with a backpacking sleeping pad and our boards as a backup.

This trip will also serve as our precursor to the 262-mile descent of the San Marcos and Guadalupe rivers into the Gulf of Mexico, using the same route as the Texas Water Safari. We plan on completing this paddling trip within the year.

Board selection was a no-brainer for this trip. The Carbon Hoss will allow us to carry plenty of gear and keep our demanding pace.

We are both big dudes and know we will need the weight capacity and deck space the Hoss provides us to stay comfortable and maintain a pace.

We have trained on these boards for nearly a year now and movement upon the wide deck has become second nature. The Hoss really is boss. 

Paddle selection was likely the easiest choice we made. The double-bladed Butterknife allows us to paddle standing or sitting without having to switch paddles, which will be huge for us on long 25-mile days. We both feel strongly that a fully capable backup paddle for each of us will be crucial in the event of equipment failure. The Lock & Load provides us with a high-performance paddle that can be broken down small enough to fit in a dry bag.

Over the next few months, we will be posting plenty of updates. If you want to keep up with us, you can follow us here on Instagram @onorunderwater and @thegeoexplorer.

David McBee is an ambassador for Hala Gear.