I wanted to share a story that happened to me on my last night dive. I was diving the Will Laurie and Anthony Bell wrecks off of the west cost of New Providence. Visibility was poor, however the plan was to navigate from the Will Laurie to the Anthony Bell and back. I set my compass before the dive to the bearing, which is approximately 270°. We jumped in and without incident we made our way across. We bimbled about the Bell for 15 minutes before turning and going back towards the Will Laurie.
Now, during the day I can naturally navigate between the wrecks without any difficult and I have done the night navigation between them enough times to have a good instinct about the directions. Though I do use a compass at night just to make sure I am heading in the correct direction. However, my compass refused to show any bearing other than one between 260° and 280°. It was rendered useless.
We could have popped up to the surface and checked the direction but as the site is not more than 200m form each other we headed in the general direction of the Will Laurie. We would occasionally stop, cup our lights and look for the other divers on the wreck but no other lights were to be seen. Soon I had an uneasy feeling that we had gone passed the Will Laurie. So again we stopped. Off to our left I caught a glimpse of a light, we were the only dive boat out so confirming with my buddy we made our way towards it. We had only gone 15-20m east of the wreck but it was enough to hide it from our sight.
The remainder of our dive was spent on the Will Laurie, looking at the amazing cuttlefish and the crap that had claws as big as my forearm and a body that was as big as my head.
Once we were back on land, I checked my compass and still it gave the same erroneous readings. I flicked it to calibrate mode and recalibrated it. Comparing it with an old fashioned compass it now reads correctly. I had forgotten that my compass needs regular calibration. It is something that I will do on a more frequent basis from now on. This situation could have easily been much worse if the navigation had been more complex. I like the benefits of the compass on my dive computer but I think I’ll be carrying a backup in the future.