There is no road access to Jaibalito Lake Atitlan
The public dock at Jaibalito is served by the regular ferry boats (lanchas) that do the Panajachel-San Pedro route. As of Aug 2017, tourists should expect to pay 15Q/20Q between Jaibalito and Panajachel.
The only other method of access is via a footpath from adjacent villages Santa Cruz la Laguna and Tzununa.
If you are staying at a hotel/hostel in Jaibalito Lake Atitlan check to see if it has its own dock, so that your lancha can drop you there instead of the public dock. If you do use the public dock and need help carrying any luggage to your hostel/hotel, there are a couple of tuk-tuks that are able to navigate the small narrow road system in the village.
There are usually a few kids that will very happily carry your bags from the dock to wherever you are staying. These kids thoroughly deserve some small payment, which they will tell you upfront.
Even if you can manage your own bags, give a thought to these little entrepreneurs. This is a very poor village and encouraging payment for work is far better than begging.