Chalk is the one area where you need to be a bit creative. An ordinary chalk bag is pretty useless after one swim. The solutions I have seen are:
1. Liquid chalk topped up by chalked shorts/forearms that you dab your hands on as you go.
2. Small drybags around the waist used as a waterproof chalkbag
3. Sandwich bag in the chalk bag
4. Cut bottom off a plastic water bottle, string on some cord and fill with chalk.
Depending on where you are climbing I'd definitely take some sort of rope for water exits. Even at popular crags like Diablo the exit ropes that are normally established and in place in high season in september might have been broken or damaged by winter storms. If that's the case it can be VERY difficult to get out when soaking wet and tired.
Take some slings and screwgates, plus a decent length/s of old rope. Tie big looped knots (alpine butterflys) in the rope every half meter or so, so you can put your feet in them and stand up in them and climb out.
In reply to blakey21: Seconding what Gus said there about short bits of rope for water exits. A few wires / hexes to hang these ropes off. Cheap dry bag can be useful as you can sometimes swim in, clamber up just above the water and dry out in the sun before climbing.
A dingy would be a good idea, most accidents in DWS are due to difficulties in the water. My best mate drowned in mallorca on the swim between where he fell and the exit point and would have probably survived if he'd had some sort of inflatable, he was a pretty strong swimmer but just didn't make it back to the exit.