Dive ladder steps

[Akimbo]

Has anyone ever seen/tried a Christmas tree ladder with alternating steps?

Yes but diver's aren't as stable on a rocking vessel or in a swell. Sometimes you need both feet on the same plan for maximum stability to hand gear off or just catch your breath. Not recommended for divers' ladders.

Of course we are speaking in general terms. Something that works fine less than 2' or 600mm off the water is less demanding than with 5x+ as much freeboard. It's awfully easy to get spoiled by elevators, but the same can be said of diving bells launched through moonpools on dynamically positioned DSVs. To be honest, I'm surprised that elevators aren't standard on larger liveaboards even in the tropics.

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A larger boat would can support a platform large enough for two or more divers. It's not that complicated.

 

[The Chairman]

I like a slanted ladder with railings on the side, at least to the water line. After that, I don't care. Flat, round, oval, it's all the same. I dive in real boots, so whether they're small or not doesn't matter.

 

[NothingClever]

Grippy tape on the bottom step is on my permanent wish list....

(Why is this so rare....?)

Go big....grippy tape on EACH step.

 

[chillyinCanada]

I like a slanted ladder with railings on the side, at least to the water line. After that, I don't care. Flat, round, oval, it's all the same. I dive in real boots, so whether they're small or not doesn't matter.

I used to dive in real boots, still didn't like small rungs.

 

[The Chairman]

I used to dive in real boots, still didn't like small rungs.

My first dive off of a boat (mid-seventies) was epoch. Off of Ponce Inlet, and it didn't have a ladder. Even without gear, we couldn't get over that gunnel. We were towed back in. I'm pretty cool with any ladder on a boat.

 

[Mike Walker]

Go big....grippy tape on EACH step.

Boiled frog technique...

The last time I mentioned this to a boat captain I got looked at like I had 3 heads and there was some mumbling about grippy tape being expensive.

I figure if dive ops can dig into their couch cushions for at least 1 roll and do the bottom step on each boat we've moved forward and perhaps - in 20 to 30 years - sanity will prevail more broadly.

I've thought about bringing rolls of it with me and leaving that instead of a tip...

 

[Akimbo]

I suspect that the biggest complaint with abrasive non-skid tape is the lifespan on narrow metal rungs. Corrosion under the tape tends to make it peal up so it is a maintenance problem.

IMO, diamond plate isn't non-skid enough around diving. The ideal solution is a rubber-like non-skid matt that is screwed or riveted down on wider flat rungs. I have seen expanded metal steps/rungs, which are outstanding for work boots, but are too hard on wet and suit boots for dive ladders.

We used donated fiberglass grating with embedded grit on the top surface for the submersible swim step on the Lift to Freedom elevator. It is super rugged but is uncomfortable on bare feet. That isn't a big problem in cool climates like Monetery but would't be good in the tropics.

 

[Mike Walker]

I suspect that the biggest complaint with abrasive non-skid tape is the lifespan on narrow metal rungs. Corrosion under the tape tends to make it peal up

So, in other words it has the added feature of a built in indicator as to when it needs to be replaced?

so it is a maintenance problem.

I don't see the problem... when it looks like it needs to be replaced - replace it....

Same for the ladder itself.... operating/maintenance costs are a normal part of business - owners need to budget for them and charge accordingly.
Staff and materials.
With the boat in post 13 I assume they just give out tetanus shots at the surface interval....

There are many possible good solutions here... even some not so good ones that would be totally acceptable...but the industry standard I've run into more often than not is 'can't be bothered to even try'. However, I have stumbled upon a few really good ones (of various sizes, scales and of no specific design - but they worked perfectly for their environment) so it's entirely possible to do it well with a bit of thought and effort.

Certainly appreciate the OP in this thread doing just that.

 

[MaxBottomtime]

The Armstrong ladder I use has flat stainless steps with a non-skid plastic cover. I had a modified swing bracket welded and added non-skid tape to the railings on the swim step. We've used this ladder for several years including double steel tanks with a deco bottle. It is angled and very easy to climb in full gear.

 

[Akimbo]

I don't see the problem... when it looks like it needs to be replaced - replace it....

Understandable, but easier said than done. This stuff can be very hard to get off even though outer edges are not adhering. That's why you see so much non-skid tape peeling on most boats in the marina instead of being promptly replaced. Something like the Armstrong ladder's molded rung covers are a much better solution but requires very expensive tooling. Not a problem if you can sell thousands of them.

There is a design compromise at play. Rungs on most shorter Christmas tree ladders, like @MaxBottomtime's Armstrong, use the rungs as hand-holds. They can't get much larger without making them too large to grip -- especially with small gloved hands. Larger flat steps are more comfortable and stable, but are useless as handholds. This problem can be resolved by adding vertical handrails near the center but that adds weight, bulk, and cost.

You really have to consider the size of the boat, the freeboard, how far below the waterline it projects, and how you stow it. A good solution on a small private boat probably won't scale to larger dive charter boats and definitely not to DSVs (Diving Support Vessel).