Seac BM30 Fins
Salvimar Freedive Computer
11 September 2023
Saplast: A Sea of Accessories
11 September 2023
The SEAC BM30 Fins are an interesting model, because they are characterized by a foot pocket with short rails that has an inclination of 30 degrees. They are further paired with a polymer blade with a differentiated thickness profile. This fin comes at a decidedly attractive price, around 100 euros, as per Pietro Lanzafame.
What immediately catches the eye is the foot pocket, featuring short rails and a geometry designed to accommodate the 30-degree angled blades. The short rails are intended to fully exploit the mechanical characteristics of the blade, particularly not limiting its flexibility and responsiveness. Thanks to the foot pocket/blade angle, the ankles can work in a more natural position, striking a good compromise to optimize the kick both on the surface and during dives.
Similar to the Motus line, the foot pocket is constructed using two different rubber compounds: a stiffer one for the sole, providing stability in the fit, and a softer one for the upper part, ensuring a good fit but not while sacrificing comfort.
The blade, is no less impressive; it is made of technopolymer with a differentiated thickness profile. It is characterized by its lightness and flexibility. The response during the classic "rolling" test is significant. The manufacturer guarantees a shape memory that excludes any permanent deformation, even after significant stress has been placed on the balde.
With the aim of not limiting its mechanical characteristics, Seac's engineers have designed small, anti-slip stabilizing fins. They are placed at the extremity of the blade. Their function is to act effectively at the point where, from simulations, the greatest water flow concentration is observed, while at the same time not stiffening the whole blade.
The BM30 fins are produced in a single model, with sizes ranging from 36/38 to 47/48. The size we tested (41/42) weighs 1.1 kilograms per single fin. The overall length is 89 centimeters, while the width of the blade at its widest point is 21.5 centimeters.
In the Sea: Upon receiving the BM30 fins, they immediately made a good impression "to the touch," both due to their lightness and due to the softness of the upper rubber. We used the fin multiple times in different sea conditions and we were impressed.
Since it was winter, the tests were always done starting from the shore. The first test took place with a slight outgoing tide. It is easy to wear the fins with 3.5mm neoprene socks, due to the elasticity of the footpocket’s rubber and by the tab placed behind the heel. The foot easily glides in, without any discomfort from the neoprene and once you start finning, you feel the footpocket creating a snug and comfortable seal around your foot.
The first swim was about 15 minutes long to reach a small boat just offshore. During the swim, there was no discomfort or "pressure points" on the top of the foot, ankles, or near the toes.
The spearfishing outing continued for about 4 hours, characterized by long swims and dives to depths between 10 and 18 meters. The foot position with these fins is quite natural and we could get used to it easily.
The blade exhibits a speediness that can be called upon in any given instance and at the same time appears soft. This is thanks to the absence of longer rails, which are seen on many older Seac fins. There are no dead spots, both on descent and ascent, and when the kick is very wide, the engagement of quadriceps and glutes is constant. Here, well-trained legs have certainly made the use more manageable.
Subsequent outings with calm seas allowed us to appreciate the good speed that can be achieved with a proper kick; the fin doesn't lead to "bicycling," and the knee and ankle joints do not suffer.
Later, we wanted to test the anti-slip system by diving in strong current conditions, typical of the Strait of Messina. Seac's promises were indeed fully met, as the fin, when swimming against the current, did not veer off course thanks to the system designed by the Genoese company and, we believe, also thanks to the blade's inclination.
Our final impression was that of a truly well-designed model, certainly of high-end quality, but one that is also suitable for less experienced spearfishermen who want to use something more performance oriented before switching to top-level materials. All at an affordable price (around 100 euros in various online stores). However, the BM30 truly shines when worn by those accustomed to long swims in the sea. This consideration made us curious and we had to conduct another test!
We tested them in the pool after trying them out for several days in the sea. We were thoroughly impressed by their performance, which led us to bring them along for training sessions in the pool. Our initial hunch proved to be correct - the overall geometry of the fins is well-suited for swimming close to the pool tiles during training and for narrower and faster kicks. Whether in warm-up sessions or during breath-holding exercises, the BM30 fins have proven to be excellent training fins, capable of providing comfort to the feet even without wearing socks and without putting excessive strain on the joints.
During rapid and narrow kicks, they consistently provided excellent propulsion, not overly fatiguing the legs. During the recovery phase of the kick after the gliding phases typical of dynamic swimming, they aided forward propulsion. It is precisely in this aspect that, in our view, the mechanical characteristics of this model have demonstrated their importance. These fins are well-suited for indoor apnea, and we recommend them for beginners and athletes in the early categories during competitions.
While the test provided the clear impressions described above, one question remains: should we expect any upgrades? Perhaps to the blade?
Seac's statements and the fact that we find both the "BM30 foot pocket" and the "BM30 Carbon foot pocket" options in the official online catalog, leave us wondering if there might be something more in store. We certainly hope so!
