Benthica has a wide variety of devices to collect sediment cores and surface grabs.  The corers range from a 2" Livingston piston corer which I have used to collect cores up to 17 meters long, to 5" diameter corers for collecting the top 0.3 meters where solids contents are low enough that collecting adequate mass for analyses can be a challenge.   Along with the corers Benthica uses either a hydraulic extruder for fast production of thick intervals (typically for dredging), or an incremental extruder that is capable of indexing the interface and then sectioning at as thin a 0.5 cm intervals for a length of 2 meters with no more than 0.2 cm of cumulative error.  Benthica is equipped to process all samples in the field, an important capability when media are easily disturbed, such as surface sediment, or samples that can undergo rapid chemical changes such as redox transformations.
Some years ago I decided to address the issues that make Ponar and van Veen samplers less than optimal, among these are poor closing power, penetration control, and sample access.  Pictured on the left is what others refer to as the Klein sampler.  Due to the changed routing and geometry of the closing system, it has 5 times the closing force of other grabs.  It also has no hinge across the top that obstructs access to the sample.  The arms are removable and weights are easily added.  In the middle is the 0.1 m2 box corer shown being subsampled in the field.  Benthica has auxiliary equipment for these devices that completely prevents washout of material during retrieval, an inherent problem of all “grab” samplers whose jaws do not provide a hydraulic seal.  On the right is a sediment trap freshly retrieved after a year of deployment.  These are very useful if trying to distinguish the characteristics of new sediment from previous sediment, a method appropriate for source identification.  Benthica has made over 200 trap deployments, with only 2 lost traps.