Try lubing up the traveler with liquid dishwashing detergent. I could never decide if it's a great lube or it just cleans all the crud out. In real light air you have to splash water on the track but you have lots of that.

The first time you apply the detergent, rinse the car and track out well with a hose. Spray water directly on the ball bearings and work the traveler back and forth. Next squirt some dish washing detergent directly on the bearings and work the traveler back and forth the full length of the track. Rinse well then apply a little more soap, work the traveler the full length of the track and now you are done. If the foam is gray or green on the first step you might want to repeat it. If your traveler foams up during a race, tell people your boat has rabies.

Seriously wet lubes like WD40 hold dirt and crud. After a couple of years the inside of your traveler will be full of black gummy stuff.

Also, check the inside of the traveler for "bad idea's from previous owners". I have seen people spray aerospace dry film lubes (they look like paint) or "Silverstone in a can" or ?. They turn into real thick, pitted black crud. I tried Sundstrand Sandoz on a traveler once. It was a very bad idea.