Verify your farm design with your chosen farm site.

Flat bathymetry – In the real world, many ocean farm sites have variable bathymetry—the ocean bottom might slope gently, drop off dramatically into a trench, or include peaks and valleys. The Farm Design Tool assumes that your site’s bottom is flat and the water depth is consistent across the entire site. Check the water depths at your site, and make adjustments to your gear measurements if the site is not flat.

Single bottom type — In the real world, the ocean bottom may vary across a site, changing between rock, sand, mud, clay, and other substrates. The tool assumes that there is a single, consistent bottom for the entire site area and that a single type and size of anchor will suit every array on your farm. Check the bottom types at different areas of your site by dropping a weight or diving your site. If the bottom types are different, you may need multiple anchor types, sizes, or scope ratios.

Growline length limits — The Ocean Farm Design Tool relies on empirically validated mathematical formulas in order to calculate the holding power required to secure an array and recommend an appropriately sized anchor. These formulas have been tested on longlines from 50-600 ft. for a single-line array and 100-400 ft. for a 5-line array, which is the current limit for growline length. If you plan to use a longer growline, you should verify your designs with an engineer.

Get creative

Combine array types — In the real world, there’s nothing stopping you from combining different types or lengths of arrays within a single farm design, either for R&D purposes or to maximize yield within an irregular site. However, the Ocean Farm Design Tool currently only supports a single array design, either a single- or 5-line array, replicated over the site area.

If you plan to include multiple array types on your farm, you should update your farm diagrams accordingly.

Consult with a qualified engineer. 

Conservative calculations — The mathematical formulas used to calculate anchor holding power requirements attempt to take into account all forces that are acting on a longline when it is in the water. Current velocity is a critical component of this, as is current direction relative to the growline. In most scenarios, you will want to orient your arrays parallel to the current to minimize drag forces on your lines. However, for the purposes of this tool, we err on the side of caution by assuming that the current runs perpendicular to your arrays, resulting in recommendations for more holding power and larger anchors. 

Always consult with a qualified engineer before deciding to use smaller anchors than recommended.

Verify yields after your first harvest

After you have a season of farming under your belt, you should check your yield numbers. In the tool, to predict yields, the maximum length of a sugar kelp blade is assumed to be 16 feet and cannot currently be changed. This is to support the tool’s conservative calculations. Yields are calculated by multiplying Estimated Yield Per Foot by Total Growline Length.