Getting There & Departing
By Car or Taxi -- To get to Isla Grande, you'll want to continue past Portobelo along a pockmarked road for about 20km (13 miles) to La Guaira, an impoverished fishing village with two piers: one with boats to the Bananas Resort and, 2km (1 1/4 miles) beyond it, the pier for boats to Isla Grande. You can park at either dock, but the Isla Grande dock charges a $2-per-day fee (£1). And upon your return, you can count on some slacker or young kid hanging around and asking for a $1 or $2 (50p-£1) for additional "security" when you leave -- and they're not nice if you decide not to pay. If you really want to get out of paying this "fee," simply ask how your car looks. Likely, they have no idea.
There are few taxis in Portobelo to get you here, but if you find one, expect to pay around $10 (£5).
By Bus -- For buses from Colón or Panama City to La Guaira, you'll need to follow the same procedure you would for Portobelo, but catch a bus to La Guaira instead of Portobelo when transferring in Sabanitas. You'll be dropped off at a small port from where you'll have to take a $1.50 (75p) water taxi to Isla Grande.
By Water Taxi -- The Bananas Resort includes water-taxi service to their resort for guests staying there, or for those visiting on a day pass. Boat taxis at the public pier charge $1.50 (75p) one-way to Isla Grande, or $3 (£1.50) per person to Bananas. (They'll sometimes charge a $10/£5 minimum if there aren't enough people.) When the sea is rough, you might get a little wet.