Clifton Harbour is protected by a big barrier reef and is very popular spot for cruisers.
Moor: the buoys belonging to the Tobago Cays Marine Park are located close to the reef and have TCMP written on them. A park ranger will come to collect the fee, $EC60/night or $EC150 for 3 nights and with a 4th free. If a boat boy helps you with the mooring, they are supposed to give you their card to pass on to the park rangers who will then give that boat boy a commission. If the boat boy asks you to pay him directly, tell him you cannot pay him unless he provides a receipt.
Ashore: good for provisioning, go in the morning for fresh fruit and veg. Always ask the price before buying. Bars and restaurants in the village are worth visiting.