Offset gates, or staggers, are a series of 3 or more downstream gates that alternate between one side of the river and the other. Right-left-right, or left-right-left. They are often the most difficult gates on the course.
There are some alternatives to just going direct for offset gates. You can do one or more gates as a reverse gate. If you practice reverse gates, this can make the offset combination easier, but sometimes it is slower. It is important to practice reverse gates so that you are proficient at them before you get to a big race. You usually want to have already completed the turn for the reverse before the gate and then have your boat moving across as it goes through the gate in the direction you want to go next.
Another alternative is to do a little back ferry move between two of the gates. Have your boat at an angle to the current and moving slowly downstream. Take a back stroke or several back strokes to move the boat across the river to a point just above the next gate. This is also sometimes slower because you lose the boat speed or glide of the boat when starting to back. However, sometimes it is used as a plan B in case you make a mistake on the course and are out of position, and you can save the move by backing. And sometimes it is a good plan A because it sets you up to get a good approach for an up after the offset sequence.
But the basic way to do offsets is to go forward. Direct. Make sure you have a good line at the beginning of the offsets because if you start getting behind, you will have troubles later. On hard offsets on fast water, like we often see at World Cup events, have the boat sideways to the current for the first down gate. Then, do a pivot to turn so the boat is sideways for the second gate. If you do this, the turns are done before each gate so that they bow isn't up in the air as you are going through the gate, which can lead to a touch.
This may seem counter-intuitive, but you don't want to aim your boat for the next gate. That is the natural tendency. You see the next gate, so you look at it and that is where you go. Instead, you want to have the boat sideways to the current at each gate and aim way upstream of the next gate. That way, you can get the turn down well ahead of the next gate, so the boat is pointed upstream of the gate following it and cross-ways to the current each time.
For easier offsets, you don't have to have a sideways angle to the current for each gate, but you should still get the turns done before each gate. That way, you keep the boat speed going better and you are set up for each gate in the sequence.
A workout that is technical, yet not physically demanding is to set up a series of offset gates in hard, fast water. Then, carry up for each run. With all downstream gates, you don't get tired, yet you are practicing some hard moves. And not paddling up but carrying up means you get a long rest between runs and you don't have the extra fatigue of paddling back up.
Sometimes, one of the down gates is in an eddy. If that is the case, you usually do not want to be angled as you go through the gate. You won't get washed downstream. Just go straight through the gate and do a pivot as your body crosses the gate line and then turn the boat back upstream before you enter the current. Do not enter the current with the boat sideways and no speed as then you will get immediately peeled out and go downstream.
Practice offsets often. They are hard technically and important skills to learn for whitewater slalom racing.