Speardiver wetsuits have open cell neoprene on the inside. For those not familiar with open cell, it's smooth neoprene without a lining. It's the material that needs to be lubricated with a mixture of water and hair conditioner to allow you to effortlessly slide the suit on. Lack of interior lining allows the suit to be much more flexible/comfortable than a double lined suit, and completely eliminates water circulation inside the suit which translates into warmth. Open cell neoprene is sensitive to tears. But the only time the open cell neoprene has a chance to be damaged is when putting the suit on carelessly ie. grabbing the neoprene with fingernails and pulling, or storing the suit inside out.
At all other times the Lycra lined outside of the suit offers the same protection and durablity as the best lined scuba suits. The lining resists continuous abrasion such as when sliding in and out of a kayak, and occasional serious abuse like being rolled in rocks by the surf.
The seams are very well glued, with the glue having high heat resistance. This means your suit will not come apart if you leave in the car on a hot day. The stitching is also top notch. I have never seen our suits come apart at the seams.
There is full length elbow elbow protection, and knee pads, both made of supertex. Basically the suits are very durable, comfortable and warm.