One of the best ways to prolong the life of your sea-fishing reel is to put a protective cover on it on the way out to the marks and again heading home. This not only stops the reel getting knocked about but will stop the saltwater getting driven inside which on some reels can make the drag slip and let salt into the bearings causing them to wear.
Even if using a cover still always rinse off under a fine spray of cold or warm, fresh water and leave to air dry. Never submerge the reel or use hot water as this may degrade the oil and grease in the reel. Similarly, if using WD40 do not spray it where it can get into the inside of reel, as this will wash the grease out and do more harm than good. Best bet is to spray onto a rag and wipe the reel over.
Now and again, put a little oil on the level wind and the handle.
Have the professionals take care of your reel by contacting Dave at the Reel Service Centre.