There are boat tours on the klongs, the small canals that pass through Bangkok, leaving from each end of the market. They last 1h30 and cost 99 THB per person. I recommend you to make one, it shows a surprising facet of Bangkok and combines a floating market visit and a tour on the famous Bangkok klongs . Moreover, on weekends, when klong Lat Mayom market is open, the tours on the channels offered from the various piers of Bangkok often include a stop here for lunch.
I also advise you to combine the visit of this market with Taling Chan Floating Market 9 km away, starting rather with Taling Chan market. There is a red songthaew with a white sign (pickup that is used as a local bus) that connects the two markets for less than 10 THB per person.
To go visit Klong Lat Mayom Floating Market, you can also book one of the tours above.