The short trip to the reef and its pools is made with a raft using a small sail almost as decoration, since most of the way is made with the sailor pushing a paddle against the reef.
Asking him if it wouldn't damage the reef, the answer was "No", but I was not too convinced.
Taxi's in Porto
I think that if you speak Portugese (which I cannot) you can negociate some prices, but when we were there it was 8 Real's(each way, regardless of how many passengers) from most of the hotels to the center of Porto. Very few of the taxi's are marked, but don't worry, they won't let you walk by without asking if you need a ride.
Rent a car
Before get there, or to get to Recife Airport try to rent a car with or without driver. You may get it in normal agencies or in internet. Ininternet you may reach one of the hoptels there and usually they know someone that may reach you from the airport and show the local views. It's cheaper than to hire a Buggy with a "bugeiro" every time that you want to go to some place. You may also program in advance a trip to Olinda, Recife, Maria Farinha, etc.
We took the bus from Guararapes airport in Recife.
The first bus leaves Recife airport at 7:30,and than every hour till 19:30.
It costs only 3,50 reais.
The same from Porto to Recife airport,the first one at 04:00,and from 05:30 every hour.
Taxis cost 100,00 reais for 4 guys.
There are special mini buses for up to 12 guys,from Recife airport,and it costs about 200-300 reais return.
3,50 reais is for one way!