Ynetnews.com reported Egyptian forces made the arrests after the guards threw weapons overboard, raising suspicions, when the yacht encountered an Egyptian coast guard ship Wednesday.
The Egyptian forces took the Israeli guards -- three men and a woman -- to Sharm el-Sheik for questioning, officials said.
Israel's Foreign Ministry told Egyptian authorities the incident resulted from a misunderstanding, Ynetnews.com said. After interrogation, the guards were released to Israel and arrived aboard the yacht Sea Bell in Eilat, Israel, Friday.
Israeli security guards work on cargo ships passing near Somalia where piracy is common.
The Sea Bell offer tours in the Red Sea, Ynetnews said.