You have a steering cable from the handlebars to the rear of the ski’s jet drive that is metal and slides inside an outer cable covering. They get corroded over time and can sometimes break, leaving you without steering, which is not fun, I can imagine. You can try WD-40 or another lubricant spray to see if it will improve and lubricate the sliding action, or just replace the cable. I sometimes pull off the rubber fittings on each end of the cable, where you see the inside cable slide into the outer covering. Then I spray a lubricant into the cable, as much as I can, and then push the rubber fittings back on. It is tough to get to the one under the handle bars, but I do it. I think it has helped my ski steering stay pretty smooth, and I ride in salt water often. But you might want to have the peace of mind to just replace if you have a very sticky cable. You also have a similar cable for your reverse lever, but you don’t use that as often, so it may also need the same attention.