In Trinidad, Port of Spain is the best base for seeing most of the island's sights, as you can easily get there and back in a day. However, if you plan on exploring the northeast coast – Toco, Grande Riviere and beyond – it makes sense to overnight in Grande Riviere, as the drive in and out is long and demanding. Some of Trinidad’s best birdwatching areas, such as Aripo Savannah and Caroni Arena Dam, are ecologically sensitive and all visitors need a permit to enter. These can be obtained independently, but it’s time-consuming and difficult. Far better to let a recommended tour operator handle it for you.
During turtle-nesting season (March to August) you must have a permit to enter key nesting sites such as the beaches at Matura and Grande Riviere after dark. These are available from Nature Seekers in Matura and the Grande Riviere Nature Tour Guide Association, and are provided when you sign up for a turtle-watching trip.
You can drive right around Tobago in a day, so it's possible to see the sights from wherever you base yourself. As in Trinidad, unless you're on a tour with a local company, you'll need your own vehicle to explore, as public transport isn't a convenient or reliable option for most places of interest.