Professional Spotlight: Santa Cruz Harbor Sediment Mapping

Finished Survey

Blake Anderson is the harbormaster at the Santa Cruz Harbor in California. As harbormaster he oversees all the operations of the harbor, harbor patrol staff, which includes search and rescue, law enforcement and public safety. He also oversees administration of about 1000 boat slips and day to day operations of the harbor. 6 years ago, Blake was faced with the challenge of rapidly mapping the constant shifting sand shoals in the harbor and turned his attention to BioBase as a potentially rapid mapping system

During the winter in Santa Cruz, northwest swell and southerly storms cause the rapid build up of sand in the harbor entrance, the harbor needed a way to identify where that build up was happening and found BioBase as their solution. Before BioBase, harbor employees would drive in a grid pattern and look at the depth finder and correct for the tide in their heads. The methodology was not consistent for data collecting so they were looking at a way to incorporate electronics on the boat as an easy way to run a route and create a map. Lowrance and Simrad depth finders have a built-in option to create a route and with the addition of autopilot consistently mapping the same areas is easer than ever.

Entrance Shoaling
Historic look at Entrance Shoaling

There are two main reasons why mapping the sand in the harbor entrance is so important. First is public safety, the harbor releases weekly maps of how deep the entrance is at that given moment. In the winter time the channel markers are removed due to environmental conditions so BioBase maps are uploaded to the website as often as possible to help boaters stay safely in the channel when entering. The maps also alert those with deeper draft vessels to the possibility of shallow conditions. The second is the harbor uses BioBase maps to plan and inform regulators with their intent to dredge on a yearly basis. During dredging operations, the harbor performs 3 or 4 soundings a week to give the dredging crew a good idea of which way the sand is moving and where to dig. They have created an overlay in photoshop over the top of the BioBase map that lines up with quadrants for easy reference as well as the federal channel markers to help guide dredging crews during the process.


Finished Survey
Santa Cruz Harbor BioBase Survey with Master Overlay
Santa Cruz Harbor with Shoaling
Santa Cruz Harbor with Shoaling

When asked about why Blake uses BioBase, he said the public really love the maps and how they look. They comment on how readable, simplified, and accurate the maps generated are. He also is able to quickly train new employees to use BioBase due to its ease of use and inuitive user interface. Blake was able to create a step by step guide for his new employees to accurately map the harbor consistently using BioBase and Navico-branded depth finders (Lowrance and Simrad).

Santa Cruz Harbor BioBase Boat
Patrol Boat Performing BioBase Survey

Blake spoke highly of the tide offset feature and the overall accuracy of BioBase. Every now and then Blake would double check the depths against the maps using the depth finder and physical measuring methods only to find very little if any variability.

Dredging is heavily regulated with many federal (US Army Corps of Engineers, National Marine Fisheries Service, NOAA – Monterey Bay Sanctuary), state, California Coastal Commission, CA Fish and Wildlife, State Water Board, and local (Monterey Bay Air Resources Board) layers of regulation and approvals. BioBase gives the harbor the opportunity to show regulators their problems with sand in near real-time. Regulators will accept BioBase maps and the Port District sends pre and post dredging maps to them to keep them updated on the process. The maps are made available to the boating public in a variety of ways. Hardcopies and in the office while digital copies are on the website and even sent out to slip owners when shoaling occurs and warn owners of the dangers it presents via email especially during times of severe weather.

Dangers of Santa Cruz Harbor Weather
Storm Surge Present at Santa Cruz Harbor during storms of Jan. 2023

“For its cost, it’s a no brainer” Blake mentioned when speaking about the current cost of BioBase. BioBase is free for environmental agencies and non-profits like the Harbor District. The Simrad sonar they already had on the boat for other purposes before BioBase. So really, the only cost Santa Cruz harbor is incurring with these surveys is staff time and fuel to do the mapping. So yep, no brainer. The concept of “fit for purpose” mapping is highly relevant when compared to commissioning a highly detailed and relatively costly hydrographic survey from an Engineer firm each time sand blows in to the harbor. BioBase is the perfect fit for this purpose! For more information on how other industry professionals are using BioBase check out other professional spotlight’s.

Author: biobasemaps

BioBase is a cloud platform for the automated mapping of aquatic habitats (lakes, rivers, ponds, coasts). Standard algorithms process sonar datafiles (EcoSound) and high resolution satellite imagery (EcoSat). Depth and vegetation maps and data reports are rapidly created and stored in a private cloud account for analysis, and sharing. This blog highlights a range of internal and external research, frequently asked questions, feature descriptions and highlights, tips and tricks, and photo galleries.

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