If you have a Duraflex Diving Board and the non-slip surface is starting to show signs of wear, the ONLY acceptable "fix" is to send your diving board back to the Duraflex Factory for inspection and refinish.
Despite what you may hear from friendly sales people at Swimming Pool Supply Stores, there are NO acceptable products sold that you can use on your slippery (Duraflex) diving board that are approved by the Duraflex Factory. The question becomes, what can you use on your diving board to get you through the end of the season at which time you can then send your diving board back to Duraflex for a factory refinish. The factory approved answer is "3M Safety Walk Strips" that are sold at most big box or hardware stores around the country.
As you can see in the picture above, the adhesive backed stair tread strips are placed ACROSS the diving board with a half inch space between them. This spacing allows water to run-off the side of the board. Normally, you need cover only the last 24" - 30" of the diving board (out over the water). Be sure to periodically check these to make sure they are all in place and securely attached. You may need to replace one or two as the season progresses -- it just depends. As soon as the season ends, contact Springboards and More to arrange pick-up and shipping of your diving board back to the Duraflex Factory. While at the factory, your diving board will undergo three different inspections and in most cases be approved for refinish. A factory refinished diving board looks brand new and includes new rubber channels, a new number strip and new attachment bolts. The approximate cost with shipping in both directions is about 1/3 the cost of a new diving board so it is an economical way to extend the life of your diving board.