Something for ocean currents...

[LclDiver]

Another way you may be able to do it is using a jon line. These are typically used to attach yourself to the descent/ascent line while making deco or safety stops. They help to keep crowds away from the main line and keep you from going up and down with the waves if the boat anchor line is your ascent line. These usually have a carabener on at least one of the ends and a hand loop on the other. Getting better at taking pictures while fighting current, bouyancy etc is always a good practice but it is nice to have a little extra safety. Plus, if the ascent line is crowded it will come in handy there too.