Derald is an avid observer, who has travelled worldwide for the most unusual occultations and eclipses. On November 22, 1989 using binoculars, Derald timed an occultation of a 7.1-mag. star by (15) Eunomia from the Amazon River, the only asteroidal occultation known to have been observed from a ship. On April 23, 1998, he and wife Denise observed the rare simultaneous lunar occultations of Venus and Jupiter from Ascension Island. On October 19, 2005, he timed an occultation of Regulus by (166) Rhodope from Portugal along with several other observers.

To date, he has seen 45 eclipses, and collected data on many of them for IOTA’s long term solar radius study.  Derald has also helped with the early promotion of grazes and has maintained the Occultation Newsletter archives since the 1980’s.