While faster than a cruise ship, dirigibles have in the past flown around 80 miles per hour. Jetliners fly at 500-600 mph depending upon the wind (i.e., jet stream). The wind would be a problem - planes fly around at least some storms (e.g., thunderstorm cell). I'm not sure the dirigible can fly fast enough to get around storms at presumably lower altitudes they are flying.

While the last source suggests (speculates) dirigibles can fly 250 mph this seems too much - the pressure on the thin fabric would be too much. So I think the time of travel would be an issue.

Whether it can avoid the ash ... perhaps because it is flying lower. The dirigibles are propeller driven but presumably by a turboprop which is a jet engine that drives the turbine (prop) and more efficient at lower altitudes as the propeller has air to grab.

Bottom line - I fly a lot trans-Atlantic - 10-12 hours on a plane is long enough. I don't forsee a dirigible ever flying fast enough or comfortable enough for those long flights.

Disclaimer: I'm not an aviation engineer so I don't know precisely how the modern dirigible flies.

In the 1980s and 90s, several companies tried to popularise dirigibles, for small industrial uses and tourist (observation) flights, but cranes and helicopters were found to be more useful in these applications.

In theory, these uses make sense, but in practice the airship's major strength turns out to be its main drawback, too.

The wings of an airliner are broad enough to lift it, even though the pressure drop (lift) over their upper surface is fairly weak (the upper surface does most of the lifting; low pressure here 'sucks' the wing upwards much more than the raised pressure below 'pushes' it).

But the airplane makes the pressure drop by 'punching through' air.

Because it is buoyant, a dirigible (like a hot-air balloon) becomes a part of the air mass around it. There's the problem. Trying to move an airship in any direction within that air mass causes low pressure behind the craft, which pulls it back very strongly.

Airships have always needed hugely powerful engines to propel them relatively slowly through the air. And because the air mass around it is almost never standing still, the craft can easily be pushed off-course or blown away completely.

Very few airship disasters resulted from fire. Fires often resulted from a crash caused by a lost fight with the weather(and the most famous fire, which brought down the Hindenburg, may have been caused by sabotage).

Airships filled with flameproof helium crashed too, such as the Shenandoah which was torn apart by being lifted and dropped in the turbulent air of a thunderstorm.

Taking off and landing were especially dangerous, and some airships were lost while simply being taken out of the hangar. If they had been more successful in the air, the amount of space they need for parking and ground manoeuvres might well have made them uneconomical anyway.

When flight was first becoming available, HTA (heavier-than-air) machines won supremacy because they could fly faster, more accurately and with more agility on fewer engines.

(Recently, some wing-shaped types of dirigible were tried out. The theory is that you can use a smaller amount of helium to lift the load if some lift is gained aerodynamically. What's not known is whether the best combination of 'wing lift' and 'buoyancy' will include any buoyancy at all, because the smaller you make the machine, the less space there is for gas + load)