Anchoring your boat

[CW2008]

For you guys who dive from your own boats - how do you anchor your boat? I'm planning on diving from mine starting this summer and I just wanted to see what some of you experienced guys have been doing.
Thanks in advance.

 

[DennisS]

I use an E-Z anchor puller, about 50 ft of chain and 400 ft of 3/8 stranded nylon

 

[PatMyGreen]

Well this goes back to when I was running a boat just for me as well as now as a dive op. Over popular dive sites we prefer to send a diver down to tie us into the wreck at a specific point on the site to allow room for other boats AND because sometimes anchors drag or winds shift and the line isn't where you left it. To do this we have twice the depth of the water in line length plus about 10-15' of 5/16" chain and a carabiner on one end and a float on the other. The boat pulls over the site and the diver splashes in with the line. If noone is available to tend the line as it peels out then you get it all off the boat as you drift away and just pick up the diver when he is at the float again. Hands down the safest and most secure way to wreck dive, but more labor intensive than an anchor. Depending on the size of your boat you may want to use a carolina rig to make descent easier from the stern of the vessel.

If we are truly anchoring it is a good idea to have 1' of anchor chain (5/16") for every foot of your boat's LOA, at the end of as much nylon line as your boat can hold in its locker. The best way to anchor over a spot to have the boat over the top is to approach it from down wind so that your heading is straight into the wind (and therefore the surface current, at least here in the N Gulf), spot the site and then motor forward another 100-150' and drop anchor. Once you have let reasonable scope out you should let the line pull tight and give it a few moments to make sure it is set. Some people like to throw a jug on the site as they pull over it to use as both a down line and a visual marker to help anchor, others are fine eyeballing the GPS.

Another way to go is (approaching into the wind) pull over the site and as soon as it disappears from the bottom, to drop anchor. This way as you descend on the anchor line the site will be directly ahead. The advantage is that if the divers can't find the anchor after the dive they will surface in front of the boat instead of at or behind it which is more likely with the other way of anchoring. The down side is that you will not safely be able to use an anchor ball to retrieve you anchor and one of your buddies will have to raise the anchor to avoid it getting snagged on the site, assuming you are on a high relief site.

The best way to anchor if you have just a few people diving in teams is to simply live boat. Drop a marker jug on the site and they use that as a down line but can ascend anywhere they want and the boat just picks them up. This is great for spearfishing but a bad idea on a public number since the divers are at risk from other boaters. The divers should have SMBs and audible whistles if you live boat.

My $0.02

 

[Hetland]

Thanks to Captain Pat for an informative post!

Use 3 times the depth for your anchor line: 80ft depth = 240ft of line. More for heavier current/wind, less for calm conditions. I like to lean towards the longer amount of line. I think there is 10-15ft of chain on the boat I use most often. Chain makes the anchor lay correctly, so don't anchor without it. Use the biggest anchor possible on your boat without being ridiculous. After you anchor in, watch your gps to determine if you are dragging bottom.

 

[PatMyGreen]

I use an E-Z anchor puller, about 50 ft of chain and 400 ft of 3/8 stranded nylon

What he said! If you have a choice a windlass is worth every penny to the guy who would otherwise be dealing with the anchor. The anchor ball is a poor/cheap man's answer to this.

Use 3 times the depth for your anchor line: 80ft depth = 240ft of line. More for heavier current/wind, less for calm conditions. I like to lean towards the longer amount of line. I think there is 10-15ft of chain on the boat I use most often. Chain makes the anchor lay correctly, so don't anchor without it. Use the biggest anchor possible on your boat without being ridiculous. After you anchor in, watch your gps to determine if you are dragging bottom.

What he said too! They tend to sell line in 600' spools and I am a big fan of that much line because if you ever lose power its the scope and stretch of the nylon that will keep you safely riding into the waves. Also boats seem to love to break down at the worst moment so lets just assume there is a storm bearing down on you when you lose power.

 

[CW2008]

Thank you all for the quick replies. I know this is not as good a read as the powerhead debate, but very helpful to me. Thanks for taking the time to help.

 

[Hetland]

Thank you all for the quick replies. I know this is not as good a read as the powerhead debate, but very helpful to me. Thanks for taking the time to help.

I'd bet a golden speargun that anchoring issues kill more divers than sharks and powerheads combined and multiplied by two.

Pay attention to the pic that Capt Pat posted. Unless we are liveboating, we always tie a safety line at the stern with a float on the end. I'd have at least 20ft (30 is better). This is the line trails behind the parked boat. Divers waiting to board the ladder can hang here and not worry about fighting any current. This line also makes the footprint of the boat larger so that divers that surface away from the boat have a bigger area to swim to in case they are fighting a current.

Also, tie a line from the stern to the anchor line. I call this the "Granny Line" (probably 100 different names for it). This is the line that the diver uses to go to and from the anchor line (descent/ascent line). Pull yourself hand-over-hand along this line to reach the next line in the system. It will save your air and your @$$ when the current is running.

Finally, don't ever leave your boat unattended. Make sure you always have a boat OPERATOR on the boat. Make sure she/he knows where all the safety gear is, how to start the boat, how the radio works, what to do if a diver surfaces away from the boat, what to do with the anchor in case they have to leave to pick up a diver in distress, etc, etc.

I'd suggest diving with a charter or some old salts so you can see the ropes and lines in action before trying it yourself. It really is one of the most important aspects in boat diving.

 

[CW2008]

I'm much more concerned with screw ups than with sea life.

 

[PatMyGreen]

I would wager that, like Hetland said, nothing will prevent screw ups or at least minimize them as much as always having a knowledgeable operator standing by topside. If you are the only such person onboard if something happens to you..... well enough said. As a for hire captain that loves to dive and has a penchant for getting bitten by things..... this is a very important rule on my boat when I am out for fun.

 

[CW2008]

always having a knowledgeable operator standing by topside.

Advice well taken. That's why I have to get my wife trained to operate my boat. It's OK because my son usually dives with me and she would never leave me out there as long as he's with me.