You won't see many people doing this one.
The Seal Row
Why do the seal row instead of a more common row variation? Here are some of the benefits:
1. You get no help from your legs.
Other rows allow for the use of your legs to help get the weight up. With this, your body is completely suspended from the ground, so you're forced to use only your ab and glute muscles for stabilization and your lats and upper back to lift the weight.
2. There's no body English or cheating.
Since you're off the ground, you can't use momentum.
3. It's safe for the low back.
Since your chest is supported, your abs are forced to engage, and your low back will be in a much safer position.
How To Set It Up
If your gym doesn't have a tall enough bench, grab the bench you have and put it on some type of platform, like step boxes. This will get you the maximum range of motion. It's a bit harder to manage if you have long arms, but it's doable.
How To Do It
Keep your legs together, big toes touching, and squeeze your glutes to stabilize. Lead with the elbows to pull the dumbbells to your sides.
As you get stronger, you'll be able to move some decent weight but start light and work up. Try 3-5 sets of 10-15 reps. Do these toward the middle of your workout.