Choosing the right fishing weight is not a minor decision. The type of seabed, the strength of the current and the working depth all directly affect the performance of the gear: a poorly sized weight snags, loses its trajectory or wears out prematurely, with the resulting cost in time, material and catches.
At GreenCastSea, this logic sits at the centre of our product development. Our roots in the Basque Country place us in front of one of the most demanding environments in which to put this to the test: the Cantabrian Sea and the Bay of Biscay, where highly varied seabeds, rocky, sandy and transitional, combine with currents that change in intensity depending on the area and the time of year. This makes a good starting point for explaining, in general terms, what needs to be considered when selecting fishing weights for any industrial fishing ground.
Seabed types and their technical demands
Not all seabeds behave the same way against a fishing rig:
- Rocky and irregular seabeds. These favour snagging and call for weights with profiles that minimise aggressive contact with the substrate, along with high abrasion resistance.
- Sandy or muddy seabeds. These allow greater line stability, but require sufficient weight to prevent drag from the current and maintain working depth.
- Transition zones. These combine both behaviours and tend to be the most demanding, since the gear shifts from one condition to another within a single haul.
Working in an area with this diversity of seabeds, as is the case across much of the Cantabrian Sea, means the fishing weight cannot be treated as a standard component, but rather as one that must adapt to the real conditions of each fishing ground.
The role of the current in weight selection
Current affects both how much weight is needed and its shape. A strong, sustained current calls for greater mass to keep the gear on the intended trajectory and depth, along with more hydrodynamic profiles to reduce drag and prevent the weight from drifting off the working point. A variable current, or one with changing intensity, instead calls for an additional safety margin in the weight's sizing, so that the gear does not lose stability if conditions change mid-haul.
This variability is common in the Bay of Biscay, where the current behaves differently at the surface than at depth, and does not remain constant throughout the year.
Trawling in areas of variable current
In bottom trawl nets, the weight plays a critical role in maintaining the balance between flotation, opening and net depth. In areas of changing current, this balance is harder to sustain, and inadequate ballast can lead to a loss of selectivity or greater wear on the gear. Our SOKA range, designed specifically for trawling, is built to maintain stable technical performance under these conditions, without compromising the performance that industrial fishing demands.
Longlining and anchoring on irregular seabeds
In longlining and other anchoring techniques, the challenge is different: the weight must fix the gear precisely on seabeds that are not always uniform, avoiding snags and loss of material. Our SARE range, in its SA and ST models, is designed for this type of fishing, prioritising a design that reduces aggressive contact with the substrate and protects both the gear and the seabed itself.
Why the material matters too
In waters with high salinity and constant exposure, the corrosion resistance of the weight's material is just as relevant as its shape or mass. Our fishing weights are made from 100% recycled, lead-free zinc alloy, which combines high corrosion resistance with a reduced environmental impact from fishing activity, without sacrificing the technical performance that industrial fishing demands.
About GreenCastSea and the manufacture of lead-free fishing weights
At GreenCastSea, we believe it is possible to fish efficiently without harming the ocean. That is why we develop eco-friendly fishing weights for professional fishing, completely free of lead and made from recycled zinc alloy, resistant to corrosion and designed to adapt to the real conditions of each fishing ground, whether a rocky seabed, a variable current, or a trawling or longlining operation. Every model is designed to protect the seabed: it avoids snags, minimises sediment displacement and reduces gear loss.
Our roots in the Basque Country, facing the Cantabrian Sea and the Bay of Biscay, connect us to a deep respect for the sea, and that respect guides every piece we manufacture. We are committed to cleaner fishing, one that cares for both the ocean and the people who depend on it for their livelihood.