The compact strap fins are approximately 2.0 inches (5 cm) blade length (compared to our companys compact fin) for added propulsion. Skin diving (bare diving) is also a lightweight feel. Easy to carry The protrusion part of the boot pocket reduces the sole of the foot for an improved fit and convey your leg strength to the fin blade. M 23? Wearing 10.2 inches (26 cm) barefoot socks (21 ? Wearing 9.4 inches (24 cm) marine boots.