The main highlights are at sea level, but no one visits Berlenga without climbing to the top. From the beach there's a steep path, and from the fortress you may count with almost 400 steps.
It is worthwile, however!
One of the strongest sensations (sometimes even violent) of the trip is the boat ride. When exiting the Carvoeiro cape the surf is generally high, and the boat jumps, dives, and twirls enough to make most travellers get sick.
If you use to have trouble in the sea you'd better stay in the small open decks, where showers are frequent but the vision of the waves help to distract and adapt to the movements (and without smells, without the look of green faces... ). Well, it's just a warning and be sure that my teams always kept their rosy smile inside or outside.
The island is interesting for kids, but you must be very careful with them - the paths are steep and narrow, the protections are rudimentary or absent, and getting out of the paths is forbidden.
Even in the beach you must keep them away from the cliffs, because it is frequent the falling of small rocks.
The only water available in Berlengas is collected from the rain in the roofs of the fortress and restaurant, which means that water is a RARE element.
It's possible to buy expensive bottled water during the day, but you'd better try to make low use of fresh water while in the island.
The best in Berlengas is the boat circuit, along the caves, but tide may cause some problems.
Many years ago a group of visitors died inside a cave, caught by surprise. Since then, boat men are very careful, and I think that there is no considerable risk, but you must plan your visit to make the tour coincide with low tide.
Electricity is supplied in the island by a generator that stops at 10PM. It's strongly advisable to carry a lantern with you.