In my quest to get the boss key, I'm stuck at the room with the three geysers and the tektites. I killed the tektites, and I'm now trying to jump over the geysers to the other side of the room. The problem is that I can't jump to the first geyser at all. I just fall against it (see screenshot).
Note: I'm playing on the Project64 emulator (version 1.6).
From this guide, it looks like you have the right idea, but your jumps aren't quite angled right.
Use your arrows to kill the tektites across the way. The floor switch makes not one but three water spouts rise (and not in a straight line), so step on the switch and carefully jump across them to the door. Exit.
If a regular jump doesn't work for you, try a roll jump, like Cyberson suggested. You will get more distance from it than a regular jump.
Do you play 60 fps. There are some problems with the hookshot not reaching far enough and other problems, if you run the game 60 fps. Try the original and see if you get further.
