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Old 22-07-2019, 12:17   #1
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SCUBA diving from boat and dinghy

There have been a couple of mentions and I believe the topic deserves its own thread.


Most people learn how to SCUBA dive from a dive boat, usually one of the larger ones that has a practical capacity for around 20 divers, because these are cheapest for the operator and therefore are widely used for training dives. They feature an open transom with easy access to the water, and large ladders, in some cases ones designed for use with fins still on.


As a result, most people are taught to use giant-stride entries with all their gear on, and are taught to exit the water with their gear on except (usually) their fins, which they hand up to someone aboard.


What people don't realize is that this technique is all optimized for getting a large group of people in and out of the water quickly. There are many other ways to do it, that require a lot less of the boat and the diver.


I therefore offer these alternative methods, all of which I have actually used (except as noted). Some readers may be familiar with them but unaware of their benefits. Others may find them to be new techniques:


The "gear up in the water" method

A swim line is deployed behind the boat for safety, especially if there is wind or current.


The divers assemble their kit and attach a line to the tank valve or other secure anchor point. The BC is inflated, the kit placed in the water, and the line tied or cleated off on the boat. Divers enter the water with wetsuit, mask, snorkel, weight belt, and fins. The diver unties the line from the kit and dons it in the water. At the end of the dive, the diver takes off the kit, ties a line back onto it, hands up weight belt and (maybe) fins. (It is easier to get back on board with fins on in some cases, if there is no ladder). The kit can then be hauled up.



The weight distribution should allow the diver to be comfortably buoyant without their kit. In some cases it may be necessary to move some weight from the weight belt to the kit, by placing it in a pocket or on a shoulder strap. Some very small travel BCs may not have enough buoyancy to float a full tank and whatever lead is on the BC, use a different configuration if this is the case.



The advantage of this method is that it can be done even from a very small boat, including a kayak or canoe, since the changes in weight distribution can be made gradually so the boat doesn't swamp. It minimizes weight on the swim ladder. Athletic individuals may not require a ladder at all or may be able to get away with only a rope ladder or stirrup.


The disadvantage is that you have to be able to get in and out of your gear in the water. Even though it's a required skill for certification, not everyone can do it.



In a very small boat it helps to have someone aboard to move to the opposite gunwale when climbing back in so that the boat does not capsize.


Backroll

Most divers have practiced a backroll as it's a required skill for certification. On any smaller boat, it's a better way to get into the water than a giant stride. Generally, you make the backroll from the gunwale amidships, where the boat is most stable.


Whoever is staying on the boat moves to the opposite side and stays low, to keep the boat as stable as possible.



You can still take your kit and weight belt off in the water to minimize the load on the steps, either handing them up or putting them on a line for later retrieval.


Rope ladders and stirrups

There are tricks for getting back aboard. The first thing of course is to take off your kit and your weights.


Your big boat will have a ladder. Your dinghy might not, or you may want to dive or snorkel from a borrowed or rented boat, or a kayak or canoe.



Most people aren't strong enough to grab the gunwale, pull up, and muscle up. It helps to wear fins, because then you can kick at the same time, which makes a difference.


On an inflatable you can face away from the gunwales, hold onto the handles, and do a sort of backflip onto the boat:

You have to be comfortable having your head in the water, inverted, and the handles have to be in the right place and well adhered. (This is the only technique I mention that I have not tried myself)


Rope ladders are really awkward to use, but are easy to store and well suited to other people's boats. I have found that I prefer a stirrup (see photo), which I have made from a U bolt with the nuts loc-tited in place, and a strap. The strap distributes the load better than a piece of rope but either will work. The u-bolt sinks, and maintains its orientation so you can find it by feel with your foot. The idea is you set it up amidships and tie or cleat it off so that the stirrup is about 8-12" under the surface of the water. You want it to be above the chine (or above the curve of the bilge as the case may be) so that there's something for your toes to push against, but low enough that you can lift your toe to it while facing the boat.


I suggest practicing these techniques near shore or some other situation where you have a backup plan, until you're sure of them.


There are also many dive sites that are easily accessed from a canoe, kayak, or dinghy in shallow water near shore where it's easy to get in and out.


Please share any diving techniques that have worked for you.
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Old 22-07-2019, 23:06   #2
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Re: SCUBA diving from boat and dinghy

Nice write up. I dive off a small dinghy offshore Monterey, CA, which is cold (usually in the 50s Farenheit) and swelly though we won't dive in anything over 6'. Stability, when you have a lot of gear like that such as dry suit, steel tank, 45 lbs of weight, is an issue and takes practice. My buddy and I suit up together, providing a helpful hand if a belt or arm get stuck somewhere inconvenient. It helps to know your gear really well and add hacks to make life easier. When we're both ready and have checked that our air and fins are on, we roll off the dinghy, descend down the anchor line and check the anchor so we don't have to swim home. On the return, we each have a line (small rope) hanging from the dinghy with a carabiner where we can clip on our gear. We take off our belts (which are easier than integrated BCs), "throw" them in the dinghy (ha), leaving only our fins on so we can easily kick up and flop inelegantly into the dinghy. It truly reminds me of the way elephants seals haul out. I long for the days when I wore an 8 mil wetsuit because I chill easily and thought 14 lbs was a lot weight....
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Old 23-07-2019, 07:35   #3
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Re: SCUBA diving from boat and dinghy

Oh, probably no more than about 2 or 3 feet of swell to dive off the dinghy! Six feet would be too hard to manage...
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Old 23-07-2019, 07:59   #4
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Re: SCUBA diving from boat and dinghy

Easiest way to gear up in the water is to sidemount, and you can sidemount single tank.
I donít like the idea of a weight belt on that is the correct weight for an aluminum tank and getting in the water without a floatation device, many would go straight to the bottom.
Dive steel tanks and most wonít need a weight belt, or at least put the weights on the BC belt.
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Old 23-07-2019, 08:09   #5
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Re: SCUBA diving from boat and dinghy

Quote:
Originally Posted by a64pilot View Post
Easiest way to gear up in the water is to sidemount, and you can sidemount single tank.
I donít like the idea of a weight belt on that is the correct weight for an aluminum tank and getting in the water without a floatation device, many would go straight to the bottom.
Dive steel tanks and most wonít need a weight belt, or at least put the weights on the BC belt.
As a cave diver(N.Fl & Tulum,Mx.) gear up in water with sidemount is about the only way..especially tracking through the jungle for about a mile.... 😂
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Old 23-07-2019, 08:43   #6
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Re: SCUBA diving from boat and dinghy

I've thought about a SNUBA setup just to make some dinghy and kayak dives easy(er).
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Old 23-07-2019, 10:44   #7
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Re: SCUBA diving from boat and dinghy

In addition to trailing lanyards with carabiners for gear, we usually drop a milk crate on a lanyard for each divers “personal effects” or catch of the day. E.g., I don’t like doing a back-roll or giant stride with my camera rig. I’d rather get in, get sorted, then take the camera from the milk crate, assuming there’s nobody left in the boat that could hand it down. Also a handy place for tools and parts if you’re working on the boat.
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Old 23-07-2019, 12:44   #8
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Re: SCUBA diving from boat and dinghy

Quote:
Originally Posted by a64pilot View Post
I donít like the idea of a weight belt on that is the correct weight for an aluminum tank and getting in the water without a floatation device, many would go straight to the bottom.
Dive steel tanks and most wonít need a weight belt, or at least put the weights on the BC belt.

I dive a backplate & wing BC that is 8 pounds negative by itself, with steel tanks that are typically neutral. I don't use weights unless it's cold and I'm diving a 7mm wetsuit.


With a jacket BC and aluminum tank, yes, you have to put some of the weight in the BC, because the amount of weight required would otherwise make it difficult to remain at the surface without the BC.


Quote:
Originally Posted by two-rocks View Post
I've thought about a SNUBA setup just to make some dinghy and kayak dives easy(er).

I believe you're referring to the surface-supplied (hookah) diving variation where a dive tank is left aboard and a long hose (20-100 feet) is used between the first and 2nd stage.


An alternative to consider is to use smaller tanks, whatever size is easy to handle. 40, 50, 63 cf.


Quote:
Originally Posted by toddster8 View Post
In addition to trailing lanyards with carabiners for gear, we usually drop a milk crate on a lanyard for each divers ďpersonal effectsĒ or catch of the day. E.g., I donít like doing a back-roll or giant stride with my camera rig. Iíd rather get in, get sorted, then take the camera from the milk crate, assuming thereís nobody left in the boat that could hand it down. Also a handy place for tools and parts if youíre working on the boat.

Good technique to mention. I have a milk crate with a motorcycle inner tube lashed around it so it floats, that I use for this type of thing.
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Old 23-07-2019, 15:26   #9
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SCUBA diving from boat and dinghy

To give an idea as to tank sizes between Al and steel,
From left to right 130 steel, 100 steel, 80 steel, 80 Al and 63Al.
It may not make much sense right at first but the steel tanks are way smaller and less weight, but because they displace much less water due to them being smaller they require much less lead for you to dive with.
The difference in weight for my Wife for example between the weight of the tank and the lead is probably almost 15 lbs that she doesnít have to carry.
Look how much smaller the steel 80 is than the blue al 80, and an aluminum 80 doesnít quite hold 80 cu ft, where the steel does
The steel 80 and the Al 80 are side by side.
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Old 23-07-2019, 15:39   #10
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Re: SCUBA diving from boat and dinghy

Quote:
Originally Posted by gamayun View Post
Nice write up. I dive off a small dinghy offshore Monterey, CA, which is cold (usually in the 50s Farenheit) and swelly though we won't dive in anything over 6'. Stability, when you have a lot of gear like that such as dry suit, steel tank, 45 lbs of weight, is an issue and takes practice. My buddy and I suit up together, providing a helpful hand if a belt or arm get stuck somewhere inconvenient. It helps to know your gear really well and add hacks to make life easier. When we're both ready and have checked that our air and fins are on, we roll off the dinghy, descend down the anchor line and check the anchor so we don't have to swim home. On the return, we each have a line (small rope) hanging from the dinghy with a carabiner where we can clip on our gear. We take off our belts (which are easier than integrated BCs), "throw" them in the dinghy (ha), leaving only our fins on so we can easily kick up and flop inelegantly into the dinghy. It truly reminds me of the way elephants seals haul out. I long for the days when I wore an 8 mil wetsuit because I chill easily and thought 14 lbs was a lot weight....
45 lbs. with steel tanks? You are way overweighted. The heaviest student I ever taught used in the 20s and that was with Al. Tank.
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Old 23-07-2019, 15:57   #11
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Re: SCUBA diving from boat and dinghy

This is one reason I love my cat. I have a big transom "step" (more like platform) to giant stride from. I will often attach my gear to the stern cleat with a line and carabiner and throw it in, donning my gear in the water. The line goes in my BC pocket and happens to also be 20 feet long. Clip the carabiner to my safety sausage and I've got a nice safety stop depth. For the exit I clip back onto the stern cleat and slip my gear off. Then after I haul my gear aboard I can simply put the tank in the cabinet at the transom where the fill station is located.
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Old 23-07-2019, 17:36   #12
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SCUBA diving from boat and dinghy

Quote:
Originally Posted by wizoc View Post
45 lbs. with steel tanks? You are way overweighted. The heaviest student I ever taught used in the 20s and that was with Al. Tank.


I interpreted that to mean gear weight was 45 lbs. although with a dry suit?
I cave dove with a dry suit, sidemount twin steel 100ís needed no additional weight.
45 lbs of ballast would require quite the wing? But just think how you could dive bomb a wreck
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Old 23-07-2019, 22:01   #13
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Re: SCUBA diving from boat and dinghy

On a big dive boat, you alway jump in with fins on. A diver on one of my trips drowned because he jumped in without fins on feet. He had fins in hands, speargun in hand, regulator not in mouth. He struggled at surface for a couple of seconds before he sank.

Also, forget about "giant stride". Experienced divers jump in with BC deflated, and using the momentum of the jump, immediately swim to to bottom. They do not bob around the surface for several minutes before timidly dive below the surface. That is is the technique drummed into green divers.
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Old 24-07-2019, 09:49   #14
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Re: SCUBA diving from boat and dinghy

I usually gear up in the dinghy with my budy, and we both backflip in the water at the same time. Balancing the dinghy is always the fun part.

On the way out, I usually use the swim ladder, after throwing the fins into the dinghy as well as weight belt. I slowly make my way up in the ladder to give time for most of the water to flush out.
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Old 24-07-2019, 15:26   #15
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Re: SCUBA diving from boat and dinghy

Quote:
Originally Posted by gamayun View Post
Nice write up. I dive off a small dinghy offshore Monterey, CA, which is cold (usually in the 50s Farenheit) and swelly though we won't dive in anything over 6'. Stability, when you have a lot of gear like that such as dry suit, steel tank, 45 lbs of weight, is an issue and takes practice. My buddy and I suit up together, providing a helpful hand if a belt or arm get stuck somewhere inconvenient. It helps to know your gear really well and add hacks to make life easier. When we're both ready and have checked that our air and fins are on, we roll off the dinghy, descend down the anchor line and check the anchor so we don't have to swim home. On the return, we each have a line (small rope) hanging from the dinghy with a carabiner where we can clip on our gear. We take off our belts (which are easier than integrated BCs), "throw" them in the dinghy (ha), leaving only our fins on so we can easily kick up and flop inelegantly into the dinghy. It truly reminds me of the way elephants seals haul out. I long for the days when I wore an 8 mil wetsuit because I chill easily and thought 14 lbs was a lot weight....
Yes, we always did it just like that. Trying to get into your BC is more difficult once you are already in the water but still on the surface, you will breath a lot of tank air in the effort. With a buddy its much easier in the inflateable and the backroll works great.
Exiting, however, is easy when you take off the belt, BC and tank in the water and tie or clip them to a line.
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