A number of boating companies on the malecón (promenade) take turns running trips out onto the water.
Most large boats have big sound systems, a bar and a dance floor but do not make any stops where you are able to disembark. In mid-2017 the largest boat on the lake sank in front of town, resulting in several deaths. If you want to take one of the bigger boats, it's recommended to sit on the upper deck so that you can escape in an emergency.
It's more interesting to take a tour on a smaller boat. The standard tours swing past La Cruz (a monument to the flooded town of old Peñol, mistakenly believed by many to be part of the old church) and Isla de las Fantasias. Both options cost around COP$15,000 per person.
It is also possible to charter smaller boats to see the sights on a private tour. Stops include a visit to a museum dedicated to the creation of the lake and, upon request, Pablo Escobar's abandoned farm, Finca La Manuela. Prices vary depending on how far you go but start at around COP$90,000.