A warning to users, dive operators and marinas about the importance of having a contingency plan.
(Note: This story occurred outside of the U.S.)
On the morning that we left for this dive trip, there was a thick fog with almost no visibility. We left the marina at 8:30 in the morning and sailed for an hour and an half with zero visibility. When we arrived at the site, it turned out not to be the planned destination but another location.
When I checked the instrumentation on the boat, I realized that the GPS was not working and the compass was clearly broken only the VHF radio seemed to be working properly.
We did two dives and around 13:30 we started to return to the marina but after sailing for 20 minutes, the boat engine had a mechanical failure. The vessel lost propulsion due to a shaft failure. We were stuck between the islands and the shallow entrance of the bay with several freighters transiting with their horns due to low visibility. We anchored and requested help from the marina via VHF maritime radio. There are usually three support vessels at the marina but on that day, only one was available. They informed us that the boat was on the way, but after waiting for three hours, the rescue boat still did not arrive.
After radio contact with the rescue boat, the skipper said that his boat has GPS but he was not able to enter our coordinates due to lack of familiarity with the equipment. At this point, one of the divers contacted his brother who owns a speedboat. He reached our boat after 20 minutes, read coordinates off his GPS and went back to lead the rescue boat to our position. When the rescue boat started towing us to the marina, it was already 17:55 and visibility was very poor and getting quite cold.
I am reporting what seems to me to be a major lack of preparedness of the dive operator and insufficient support offered by the marina. The vessel left the marina without checking that its onboard instrumentation was working properly (only one engine, GPS inoperable, and no radar or compass), and to make matters worse, persisted to sail in almost no-visibility conditions. The marina should not have allowed this boat to sail. We were lucky that nobody on board needed immediate assistance with a serious DCS or other medical issues. Without help from the speedboat owner, the outcome could have been worse.
Beware of shabby operations! Ask always for references.