Vessel Trivial Near Miss: Boat separated from divers during sudden, extended rain

[Seaweed Doc]

Happened to me earlier this month, while diving off the south-southwest bit of Glover's Reef in Belize.

For those that don't know it, Glover's Reef is pretty remote. Roughly 40 miles off the mainland of Belize with a tiny population. Some dive boats visit, but you could easily miss them. (We saw none the day we were out, though I understood some small boats had taken divers out from the one resort on SW Caye earlier that day.)

We'd descended for our second dive (of 3 that day) and, unknown to our group of 4 (a dive guide, myself, a brand new diver doing her first dives post-certification, and an AOW diver with some reasonable experience) a serious squall came in 10 minutes after we descended and continued until a minute or two before we surfaced. The boat captain could not see the reef or island, let alone our bubble trail. He tried to maintain position a bit offshore but lost track of us. We surfaced to no boat in sight and waves big enough that you'd only see more than 20' unless you were on a crest, and even then you might not see far.

Happy ending: I put up my 6' SMB and, since the squall had ended the captain was able to motor in closer to shore where we were and pick us up.

We weren't in real danger: I know the reef there (as I hope the guide did), and we could have had a long swim to SW Caye around the edge of the reef to a break if we'd needed to get there. The experience further convinced me to take my bigger SMB when travelling to places I'm diving that don't have lots of boat traffic and easy shorelines to exit from.

 

[johndiver999]

Perhaps the lesson should be to pull a marker float, if you are not diving on a small fixed location. Is the captain unable to navigate and stay on station with GPS?

 

[Seaweed Doc]

Perhaps the lesson should be to pull a marker float, if you are not diving on a small fixed location. Is the captain unable to navigate and stay on station with GPS?

Yeah, maybe. In this case, I think the plan was a small, relatively fixed location. It wasn't so much a drift dive as a descend, swim for a bit, then ascend dive. No current to speak of.

I don't think the smallish boat we were on had a GPS unit per se, though with a phone everybody can have GPS. Even then, GPS wouldn't track the divers. (That's where the towed float comes in handy. I don't think I've ever seen these used in Belize, though. Might be some entanglement concerns when diving off walls with overhangs and such.)

The bigger issue in my mind is that we launched my SMB, not the one the dive guide maybe had or maybe didn't have. I didn't see that he had one at all. The SMB did what a towed buoy would have done in the end, immediately allowing the boat to see us.

 

[RyanT]

The experience further convinced me to take my bigger SMB when travelling to places I'm diving that don't have lots of boat traffic and easy shorelines to exit from.

For this very reason, my standard SMB is 7'.

 

[johndiver999]

Yeah, maybe. In this case, I think the plan was a small, relatively fixed location. It wasn't so much a drift dive as a descend, swim for a bit, then ascend dive. No current to speak of.

I don't think the smallish boat we were on had a GPS unit per se, though with a phone everybody can have GPS. Even then, GPS wouldn't track the divers. (That's where the towed float comes in handy. I don't think I've ever seen these used in Belize, though. Might be some entanglement concerns when diving off walls with overhangs and such.)

The bigger issue in my mind is that we launched my SMB, not the one the dive guide maybe had or maybe didn't have. I didn't see that he had one at all. The SMB did what a towed buoy would have done in the end, immediately allowing the boat to see us.

I understand, but towing a float during the entire dive provides a much easier (and more reliable) method of tracking the divers compared to a float that pops up in the general area after half an hour. When the weather turns ugly, the captain can camp out on the float and try not to lose it, even if the visibility in the rain is 100 feet or something.

If the captain has no gps and is using distant land marks to stay in a certain area, when a squall comes up, then he has no reliable means to stay on station or even know how fast he is being blown. Having a working depth recorder, a somewhat simplistic bottom profile and a good understanding of the bathymetry could help out a knowledgeable captain a lot, but I've lost divers in a squall when they were towing a float and with a GPS.

Personally, I think it is bad game to play to dive well offshore without a GPS or towing a float.

 

[Seaweed Doc]

I understand, but towing a float during the entire dive provides a much easier (and more reliable) method of tracking the divers compared to a float that pops up in the general area after half an hour. When the weather turns ugly, the captain can camp out on the float and try not to lose it, even if the visibility in the rain is 100 feet or something.

If the captain has no gps and is using distant land marks to stay in a certain area, when a squall comes up, then he has no reliable means to stay on station or even know how fast he is being blown. Having a working depth recorder, a somewhat simplistic bottom profile and a good understanding of the bathymetry could help out a knowledgeable captain a lot, but I've lost divers in a squall when they were towing a float and with a GPS.

Personally, I think it is bad game to play to dive well offshore without a GPS or towing a float.

Our of curiosity, how far is "well offshore?"

In this case, we were 40 miles from the mainland, but a "swimmable" distance from an island with at least some people on it and a means of communication. Seriously curious for your thoughts on this. Regardless, the GPS and mapping software would have been really helpful to avoid the reef, if not see the divers.

The boat we were on was too small to expect a depth sounder. I've towed floats myself in the past (not routinely, given I mostly shore dive locally), and at our location I'd have been worried about entanglement when swimming up "valleys" or past overhangs on the wall. I suppose the thing to do would be to have a second guide in the water that stays above the group and a bit off the wall and tows the float.

 

[johndiver999]

Well if you can swim to shore, then it is not far offshore. Towing a float with a lot of overheads can be a pain. If the current is low, and you use a reel, you can shorten the line so it is more manageable.