boqurant
Contributor
Necro-posting to add my 2p to this particular question now that I have a few ocean dives with the Apeks D18. For reference I've been using it with an Apeks aluminium backplate (~1.9kg inc basic harness, cam bands, metalwork), ~2.3kgs lead (5 lbs), ~1.3kg of regs, ~0.6kg assorted non-buoyant attachments (torches, computer, knife), call it ~6kgs total non-buoyant negative, ignoring gas and tank. Buoyant gear is mainly just a 2mm/3mm full wetsuit (28-31C waters). I was using a single AL80 tank, with 210bar (-1.6kg) - 50bar (+0.5kg) = 160bar = ~2.1kg of gas. So total approx 8kg negative (still ignoring tank (negative) and wetsuit (positive)) at the start, which is pretty close to the 8.16kg (18lb) of lift provided by the wing.
At the start of the dive when heaviest, I found it fine in calm waters but a fraction too low in the water in swell and surface chop. You'll want to get down off the surface quickly and not wait for laggards to get off the boat. At the end of dive when 2.1kg more buoyant - plus supported by a narrow 1m DSMB - it was comfortable in the same chop. I had the wing fully deflated on safety stop at 5m and was comfortably static on normal breathing, so my weighting seemed pretty dialed in. I'd say this is very finely tuned for calm warm waters, where it's just about perfect, but I might think twice about taking this anywhere really rough or with an expected long wait-time for boat pickup.
That said, now that I've gotten used to the handling characteristics of the wing (it's extremely nimble and takes only very fine adjustments), I could probably remove 0.45kg (1lb) of lead and still be fine at safety stop. Will report back if it improves life at the surface.
