When you gank as Nautilus, the most important thing to remember is to save your grab in case they try to escape your grasp. Emphasis on try, by the way. ;). If you simply walk into a lane with Titan's Wrath up and hit the poor fellow on the receiving end of your damage with Staggering Blow, then they will most likely start to panic and burn off some form of movement ability, such as Flash or Ghost! After they have burnt through this initial feeling of safety, slam into them with a Dredge Line and show them why they are on the wrong side. Follow this up with a Riptide, and then after a few autoattacks and of course the help of your adoring fans (The person you are helping in lane), they will either die (this is preferable), use another movement ability, or run like a coward and die to DoT. They can escape, but if they did... You did it wrong. Keep on jungling and ganking for the next ten/twenty minutes, and don't forget to give your mid a blue buff every now and then. That way the mid laner won't shout at you.