What do you consider bad diving conditions (in terms of wave height, swell, and period)?

[DMDavid]

I've had dive operators in the Florida Keys take me out in horrible conditions only because they didn't want to cancel the trip and lose any money, in the long run most of those operators have gone out of business over the years and now most put safety first.

But to answer your question, I have to admit that what I considered bad conditions when I was younger is not the same as what I consider it now. You have to gauge your own level of comfort and decide what you personally feel is safe or outside of you personal comfort zone.

For me a flat glassy day with no current (unless I'm drift diving) is a Godsend. My maximum for a great day of diving is seas that are 2-4' or less.
I have been out in conditions of pouring rain with the boat rocking side to side in seas 6-8' with light to moderate chop.
Once you get over sea conditions of 6-8' your main problem is going to be getting back on the boat depending on the type of reentry ladder or platform that the boat is equipped with, rear entry ladders and platforms tend to be much harder to reboard if they're rising completely out of the water and then crashing back down while you're trying to grab on and pull yourself out. In rough conditions I tend to prefer pontoon style boats since they're a little more stable in rough waters versus a v-hual style boat that will rock from side to side while rising and falling from front to back.

So in short I feel boat type plays a very important roll in your decision making process along with experience and whether or not you're prone to seasickness (or your dive buddy).

 

[Papasmurf89]

I'm still having trouble grasping the relationship between wave height and period and what that means for diving. For now, let's ignore whether we are boat diving or shore diving. Let's just look at it like we're already in the water and at depth, say a relatively shallow dive, 25-45 feet. I'm assuming we always want the smallest wave heights possible. But what do we look for in a period? To me it makes sense that short periods would be the worst because you're constantly going to be rocked back and forth but I've heard from other divers that a long period is bad. Would long periods be bad because the power of the rocking motion is going to be stronger?

For example, the conditions at a dive site for the next two days are:

2.5 ft (wave height) and 7 seconds (period)
1.3 ft (wave height) and 16 seconds (period)

Which would be better diving?

 

[clownfishsydney]

2.5 ft and 7 secs would be felt deeper than 13 metres (say 43 ft) while 1.3 ft and 16 secs would be felt at 64 metres (more than 200 feet). This later wave period would be give huge surge at say 60 or even 100 feet. The longer the period the deeper the effect.

This is why tsunamis have such devastating effect, they have an enormous wave period. The 16 second period waves will be moving at 90 km/h (say 60 mph) and be 400 metres (440 yards) between peaks.

A basic mehtod of working out how deep the surge will go is to count the time between wave peaks, then squaring it and then dividing by 4. This gives the answer in metres, so you will then need to multiply by 3.3 to get feet. Shallower than this and it will be worse, deeper and you should hardly feel it or not even feel it.

Hope this helps.

 

[seeker242]

I'm assuming we always want the smallest wave heights possible. But what do we look for in a period?

What you look for in period depends entirely on the height. If you have high seas, longer period is better because of the calmer surface conditions it creates.

For example, the conditions at a dive site for the next two days are:

2.5 ft (wave height) and 7 seconds (period)
1.3 ft (wave height) and 16 seconds (period)

Which would be better diving?

When wave height is small, the shorter period is better because there will not be as much surge. Both 1.3' and 2.5' are easily manageable on the surface regardless of the period. The same can't be said when the waves are big.

 

[Freewillow]

easy: I look at the face of my buddy wife. If she is not smiling, we have bad weather and we will have a BAD dive. So most of the time, I cancel it

 

[BoltSnap]

easy: I look at the face of my buddy wife. If she is not smiling, we have bad weather and we will have a BAD dive. So most of the time, I cancel it

As they say, if Mama ain't happy, Papa will never be happy

 

[archer1960]

I'm still having trouble grasping the relationship between wave height and period and what that means for diving. For now, let's ignore whether we are boat diving or shore diving. Let's just look at it like we're already in the water and at depth, say a relatively shallow dive, 25-45 feet. I'm assuming we always want the smallest wave heights possible. But what do we look for in a period? To me it makes sense that short periods would be the worst because you're constantly going to be rocked back and forth but I've heard from other divers that a long period is bad. Would long periods be bad because the power of the rocking motion is going to be stronger?

For example, the conditions at a dive site for the next two days are:

2.5 ft (wave height) and 7 seconds (period)
1.3 ft (wave height) and 16 seconds (period)

Which would be better diving?

Good and bad depend on which part of your dive you're looking at. Short period waves make it harder to get on the boat, but don't propagate down into the water as far, so cause less surge. Long period waves make it easier to get back on the boat, but the in-water experience won't be as nice unless you're going deep enough to get under the (deeper) surge.