There is a great American company called Dramm that make the best watering wands and nozzles - daylight comes second.

Even here in Australia they are the first choice for professionals and keen home gardeners.

Just google their name.

How about cover the nozzle by a thin cloth, just opinion, I never tried.
Caelian

terrygeranium, the force with which the water stream hits the earth will cause the soil to "splash".
The force is dependent upon the water pressure and the diameter of the orifice (one) of the hose - end or many in the case of the "rose" at the end of a watering can or shower head. Play around with those two variables.
I have had to adapt a shower head to the hose end because of the high pressure in the recycled water system.

Thanks all for helpful answers. I watched a couple of Dramm videos which were very instructive. Discovered that problem was not hose nozzle but, rather, me. I have been so indoctrinated to water the soil and not the leaves, etc of plant that I was blasting a full shoot of water onto the soil in the containers. What else could the soil do but leap out all over the place? The Dramm demo's showed a softer shower that also hits the vegetation above. What a difference! Now I just have to figure out how not to flood the balcony - and grateful that the occupant below is never there.

Thanks again,
Terry