Driving back to Volcano area (from Kona) after diving

[e3183h]

I searched this topic on the board and many of them were multiple dives for several days. That's why I decided to create a new topic, which might be suitable for me.

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I plan to do a two-tank Manta Ray combo dive. The dive company in Kona area informed me with the following information:

1. First dive will be approximately 60-70 feet and will be down for approximately 40 minutes.
2. Surface interval time will be 1 hours and 30 minutes.
3. Manta Ray dive will be approximately 35 feet and will last approximately 45 minutes.

All dives will be treated as no decompression dives.


Volcano area is 3,700 feet in altitude.

I look into the map and it will take approximately 2 (two) hours to drive from Kona to the Volcano area. I have never been in the area before. So, I did some researches regarding the elevation. It will gradually climb up to Captain Cook, 1,250 feet and drop to Honaunau-Napoopoo at 850 feet. It will climb up to 1,600 feet at Ocean View and drop again below 1,000 feet at Pahala before starting to climb up toward the last 30 minutes to the Volcano area.

Have anyone had experiences in driving back this direction or they should be staying in Kona area? The issue is that, several reasonable lodgings in Kona required a multiple nights stay.

Thanks for your time and response.

 

[diversteve]

I'm pretty sure Kona Seaside doesn't if you need to stay over. Should be around $125/nt. depending on when you go.
It's not great and older but would be OK for an overnight. Kona Hotel | Kona Hawaii, The Big Island | Kona Seaside Hotel

 

[scubamarketing]

I look into the map and it will take approximately 2 (two) hours to drive from Kona to the Volcano area.

You’re on island time, double any drive time you determine by looking at maps for a more realistic view. Maybe not double at night after a manta dive, but I’ve never made it from Kona to volcano area in 2 hours. I try to give a full 24 hours at sea level before going up the volcano. If it were me, I’d enjoy the dive over a few drinks, find the cheapest place in town to stay at for the night, then head back to the volcano area in the morning.

 

[knotical]

To add interest, you will also drop to very near sea level between Ocean View and Pāhala (shortly after Nāʻālehu).

One approach is to use the NOAA tables found at:
http://www.ndc.noaa.gov/pdfs/NoDecoAirTable.pdf
and:
http://www.ndc.noaa.gov/pdfs/AscentToAltitudeTable.pdf

Please note that the group letters are not the same as used by some major scuba certifying agencies (e.g. not the same as PADI’s).

Assuming worst case of square profiles and 70 feet on the first dive, according to the first table you’d be a “J” diver when you get out of the water after the second dive (if I did it correctly – please check it yourself).
From the second table, you should wait nearly 7 hours before ascending to 4000 ft.

Imponderables include:
What will be your actual nitrogen loading vs. that assumed by square profiles?
How does the time spent driving through varying altitudes affect you?

Sounds like you’d be well advised to find someplace similar to what diversteve and scubamarketing suggested.

 

[iamrushman]

+1 for all of the above...better to be safe.

 

[LeadTurn_SD]

To add interest, you will also drop to very near sea level between Ocean View and Pāhala (shortly after Nāʻālehu).

One approach is to use the NOAA tables found at:
http://www.ndc.noaa.gov/pdfs/NoDecoAirTable.pdf
and:
http://www.ndc.noaa.gov/pdfs/AscentToAltitudeTable.pdf

Please note that the group letters are not the same as used by some major scuba certifying agencies (e.g. not the same as PADI’s).

Assuming worst case of square profiles and 70 feet on the first dive, according to the first table you’d be a “J” diver when you get out of the water after the second dive (if I did it correctly – please check it yourself).
From the second table, you should wait nearly 7 hours before ascending to 4000 ft.

Imponderables include:
What will be your actual nitrogen loading vs. that assumed by square profiles?
How does the time spent driving through varying altitudes affect you?

Sounds like you’d be well advised to find someplace similar to what diversteve and scubamarketing suggested.

I concur.

I used the U.S. Navy Diving Manual tables instead of NOAA's tables (they are very similar, and I'm more familiar with the USN table layout).

I obtained a waiting period of 6:52 before ascending to 4,000 feet based on the OP's dive profile.

It would take about 2 hours, give or take, to drive to Volcano via the southern route after the Manta dive. I really would not start the drive until I'd completed the suggested surface interval.

As with any kind of decompression calculation, this is something the OP must do for themselves... don't depend on what you've read on the internet.

My advice, for what it is worth: Stay in Kona, and drive to Volcano the next morning.

And enjoy your trip!

Best wishes.

 

[Token]

I'm looking at diving in the Kohala area and travelling back to the Hilo area, so I was concerned about this too. Basically, I could see no safe way of doing this in a day. So....my wife and I found a nice rental cabin and we'll stay there overnight after my dive day. We'll do a whale watch thing the next day too. This may be a somewhat expensive way to go, but it works for us.

 

[LeadTurn_SD]

I'm looking at diving in the Kohala area and travelling back to the Hilo area, so I was concerned about this too. Basically, I could see no safe way of doing this in a day. So....my wife and I found a nice rental cabin and we'll stay there overnight after my dive day. We'll do a whale watch thing the next day too. This may be a somewhat expensive way to go, but it works for us.

Driving back to Hilo after a dive along the Kohala coast is a somewhat different situation then what the OP proposed. The altitude change is less.

I will do a single morning dive along the Kohala coast, have lunch, then drive back to Hilo. I've been doing this for many years.

However, a 2nd dive can change everything, and could require a very long surface interval. A quick glance at the NOAA or USN tables will demonstrate the increased surface interval required after even a shallow 2nd dive due to the increased nitrogen loading that 2nd dive creates.

It is completely dependent on on your dive profile, and you must do your own calculations using either the NOAA or USN tables to get a handle on the amount of time you must wait to ascend to a given altitude after a single dive, and after multiple dives.

The "safest" choice is to just stay near sea level until the next day, but that is usually not required after a typical single reef dive... but again, each diver needs to do the decompression calculation themselves for safety.

Best wishes.

 

[acooper]

It is a very long drive around the island via south point, far past what the milage would suggest. I just did that road this week, a lot of bad curves in south Kona, long lonely stretches in Ka'u district. I would be more concerned about driver/diver fatigue, particularly after an evening with two dives!

Get a room in Kona, cheap insurance!!

 

[LeadTurn_SD]

It is a very long drive around the island via south point, far past what the milage would suggest. I just did that road this week, a lot of bad curves in south Kona, long lonely stretches in Ka'u district. I would be more concerned about driver/diver fatigue, particularly after an evening with two dives!

Get a room in Kona, cheap insurance!!

Excellent point, Andrew. I get wrapped up in the decompression considerations of discussions like this one, and overlook the obvious: the danger of driving an unfamiliar and unforgiving road when fatigued.

Many of the Big Island roads are unforgiving because they lack shoulders, have short sight distances, and curves. Running off the road into a lava field at highway speed is usually a fatal event. If you are unfamiliar with the drive I would not do it at night.... and especially if you are already fatigued from a day of diving.

Best wishes.