Northwest Dive Club

Hello all,
This might be something most of you can do with easy, but I could use some help on this matter... reading tide and current charts. I would like to learn how to do this on my own, but not sure on how to make this happen.

1. How can I tell if a given site is safe to dive
2. When is the best tide
3. Sites to use to help make this decision

I did a search here, but didn't find any thing useful. Any sites that I could read up on, to learn this? Did I miss any thing?

Check out, "Seattle Tides and Currents" located five boxes below this one......

Sorry cardiver... I don't understand the following.

cardiver wrote:.... located five boxes below this one......

KneeDeep wrote:Sorry cardiver... I don't understand the following.

cardiver wrote:.... located five boxes below this one......

Go to SEATTLE TIDES AND CURRENTS in the NW Dive Club forum.
It is in the "Planning" section of the forum.....

got itm from the main page... Yeah, I had seen that, but wasn't sure how to interpret the data.

Also research each dive, usually planyourdive, or the perfectdive , and even here, have a listing/info if the site is current sensitive or not.

KneeDeep wrote:1. How can I tell if a given site is safe to dive

Do your research via the Internet, books like Northwest Shore Dives, and best of all, by diving those sites with people who have experience at those sites specifically.

KneeDeep wrote:2. When is the best tide

Generally the slack tide between the high and low is what you are aiming for. Whether it's the slack before ebb or flow can depend on the site. You also have to factor in the site's distance from the current station and apply an offset for that site.

This is actually a really good question, and it's good that you are worrying about it, because we have sites which can be quite unforgiving if dived at the wrong time.

A wonderful resource, already mentioned, is Northwest Shore Dives by Fischnaller. I'm not sure if it's still in print, though; I haven't seen a copy in our dive shop in some time.

There are a variety of places where you can get tide charts, including dairiki.org, which is what I use. But just knowing how big the exchange is, and when slack is, is not enough . . . some sites need to be dived on slack before ebb, some on slack before flood; some have eddies where the current direction will be different from what you expect, and at least one site is not good to dive if the exchange is too small! For many sites, you will find prior discussions here on what the precise timing is, but if not, this is generally a good place to come and ask, "I'm planning on diving Day Island Wall on Thursday at 3; does this look like a good idea?"

+1 on the Northwest Shore Dives, gives you the info you are looking for.

Powell's Books down here in pdx has 4 copies currently on the shelf.

spatman wrote:Powell's Books down here in pdx has 4 copies currently on the shelf.

Hey now! those are ours.

Hey, I got mine already.

Another thing that will help you out is if you go out with other experienced divers, ask them about how they planned that dive. Especially if it's one of the more current sensitive sites, ask them why the time they picked is a good tide to dive it.

Thanks all for the replies. I do feel is the most important part... the entry.

I just received a copy of Northwest Shore Dives by Fischnaller, but I left it at work and haven't had time to read it yet. Looks like I need to clean my reading glasses.

eliseaboo wrote:Another thing that will help you out is if you go out with other experienced divers, ask them about how they planned that dive. Especially if it's one of the more current sensitive sites, ask them why the time they picked is a good tide to dive it.

I would like to add to this it is good practice to ask these questions so you understand the dive planning. It is not a good idea to blindly rely on some else's dive planning. A good divemaster, instructor, or charter operator will give a dive briefing that includes tide and current information were it is relevant. Oh and don't forget it is only a prediction so watch and observe before getting in.

The entry is never a problem. It's getting OUT that can be difficult . . .

Sites really do differ. For example, Cove 2 is almost current-insensitive . . . but it ranges from a PITA to downright dangerous at very low tides, because the entry becomes so slippery and the rocks unstable. Redondo is almost current-insensitive, and the only problem at very low tides is the length of the wade to where you can dive . . . but on a big ebb, it can sometimes have a very unpredictable, extremely strong current that can be pretty unsettling. (I've crawled upslope twice there.)

The book is a very good beginning, but if you are contemplating a dive somewhere you don't know very well, it always helps to post here and say, "Is this a good time for this site?" You may have problems pointed out to you that aren't in the book, or get tips for timing.