The long and short of it is that the novel coronavirus can be experimentally aerosolized where it can persist in the air for several hours but a number of studies have failed to detect virus in samples taken from the air of the rooms of patients with active disease. But virus has been detected in aerosols near bathrooms surfaces indicates that it is spread over a long distance with mechanical assistance (flushing?). SARS was also spread by one patient with diarhoea with malfunctioning sewer systems aerolized the virus across multiple floors of a building.
Both the Covid-19 and the SARS viruses had an aerosol half-life of 2.7 hours, meaning half the particles drop out of the air after that amount of time, and half of what remains drop out after another 2.7 hours. After a day, roughly nine half-lives, 0.002 (0.2 of 1%) of the original particles remain. As a result, the scientists said, “aerosol … transmission of [the new coronavirus] is plausible, as the virus can remain viable in aerosols for multiple hours.”
The usual spread may be via contaminated surfaces (probably on the cruise ships) and respiratory transmission less so since the rate of symptomatic infection among a patient’s household members was 10.5%
Since you're outside based on the above, the viral load would be miniscule.
https://www.medrxiv.org/content/10.1101/2020.03.09.20033217v2.full.pdf (not peer reviewed yet )