The OP does not have a bio -- no location and no boat.
Kind of presume that it might be sailboat, tho. Hope he "uncloaks" and puts this info in.
If buying diesel in my sailing area, northern Oregon, we look for a source of "off road" diesel, preferably from a marine fuel dock. Price is usually higher than vehicle-intended fuels, but then there is very little sales volume in comparison. Local fuel dock owner tells us that obtaining "straight diesel" is getting more difficult each year and one of these years he (and everyone else in our geographic area) may not have an affordable source. (sigh...)
The other (big) reason is that the formulation is different - less additives.
Unlike your vehicle, that will use up fuel rapidly, the various chemicals in diesel fuel can theoretically have time to settle out when your boat is parked for six months a year. While I doubt that the contents of the tank really look like a petroleum version of a "tequila sunrise" after time passes, I have no interest in testing that theory.
I do add Biobor at each fill up, altho if on delivery and we are going to use up the tank in a day or three I skip that additive.
All risks are relative, so I worry more about getting some water in my delivered fuel than the exact blend of diesel.