Crash Bandicoot 2: Cortex Strikes Back/Hang Eight

In this level you have to go up the course of a river by jumping from one platform to another, being careful not to fall into the water. Sometimes you also have to take advantage of hippos, who dive after you jump on them. To overcome some areas you will then have a jet ski at your disposal. Driving it is easy after a little practice. While piloting the jet ski, however, you have to avoid dangerous mines that explode on contact and vortices that can suck you in. Pressing the circle button will cause the jet ski to accelerate sharply, use this button to get out of harm's way. You can break the boxes floating on the water by simply touching them. You will also find trampolines, which allow you to jump off, to break otherwise unreachable boxes or overcome obstacles. The path is very linear. You can find the crystal towards the end.

About a third of the way through is access to a bonus area. Nothing to say about it, overcoming it by breaking all the boxes shouldn't cause any problems.

Getting the first gem
The first gem is obtained as always by breaking all the boxes. To be able to do this, however, you must have already obtained the blue gem from Turtle Woods. After the second checkpoint you will find the gem on the right, which will lead you to a secret area. This area is similar to the rest of the level, but has a much higher level of difficulty. In fact, on the course of the river there are many more dangers, including the dangerous Nitro boxes. You will have to drive the jet ski with skill. At the bottom, you'll find the detonator to blow up the Nitro boxes. Soon after, you'll find the gem which will take you back to the main level, where you left off. Break all the boxes to the end to get the gem.

Getting the second gem
To get the second gem you have to pass a time trial. Upon re-entering the level after completing it, a timer will appear in the lower right right after the first checkpoint. To get the gem, you must reach the pedestal in the final room before time runs out. Certainly not easy. You have to move as quickly as possible, ignore the boxes, make the most of the acceleration of the jet ski and of course avoid dying by running into something dangerous. Of course, starting the time trial already in possession of a double Aku Aku protection can help, as you can afford to crash into two mines without wasting time avoiding them. If you manage to reach the gem in time, you can pick it up, otherwise it will fly away.