2. sunscreen: bring lots. I used 45 the whole time and we still got some sunburns. The sand is so fine, that when swimming in the ocean, the sand rubs it right off. Re-applying frequently....very frequently, is recommended. Bring long sleeved t-shirts and hats with you. Surf shirts would be a good idea.
3. repellent: bring mosquito repellent with you. Some restaurants have it available...but I kept it in my bag for use in the evenings.
4. car rental: road signs are very clear and next time, we will definately rent a vehicle. The adventures always pick you up but if you went to set out on your own and explore different beaches and restaurants it would be key.
5. credit cards: almost all places take credit cards, but some beachside restaurants only take cash....either U.S. or Costa Rican.
6. exit tax: when you leave costa rica you will need to pay an exit tax $75 per person. If you are traveling at a busy time, you can pre-pay this at a local bank to expedite your process in the airport. You need to take your passports with you when you go to the bank. Our flight was in the early a.m. We did pay our exit tax in advance...but there was no line at the airport exit tax window when we got there....In hindsight it wasn't necessary.
7. next time: next time we plan to see the Arenal Volcana and do the natural hot springs, and volcanic mud baths...