Sea freight costs a fraction of air per kilo but takes weeks. Air freight is fast but priced per chargeable kilo, which for light, bulky produce can be the volumetric weight rather than the actual weight.
Rule of thumb: if the product's shelf life is shorter than the sea voyage plus a week of selling time, it flies. Herbs, fine beans, asparagus, figs and raspberries almost always fly; blueberries from Peru increasingly go by sea in controlled-atmosphere containers.
For small buyers, the problem with air is minimums. Pooled air-freight positions let several buyers share one booking, bringing the per-kilo rate down to what larger importers pay.
