Paula the trip lasts just over half a day with a bbq on cocoa beach (johns boat tours in candolim) costs around £8 all in.
You wont be able to swim with the dolphins on the boat tour and i certainly wouldnt recommend swimming out from the beach due to the currents etc.
Gavin the house is owned by a diamond dealer called jimmy. He is getting loads of grief about it and has had to tear some of it down as it breaches the local building regs with it being built so close to the sea. However he has been paying off the local goverment to keep it.
http://www.peterferguson.nildram.co.uk/Jimmys%20house%20from%20the%20sea.JPG
2003 the prison held around 30 europeans all for drugs offences, so you really need to be careful if you are offered anything. As one time was in palolem some guy come up to me and whipped out a bag of hash asked if i smoked said no, he said good and walked away. Turned out he was a copper and if i bought any of him would have ended up in the clink.
Regards
Peter