Scooters, how FAR do you GO?

[ScubaInChicago]

So I own a couple of scooters and have used them in the St. Lawrence River under shipping lanes. I've used them off of boats in various bodies of waters. My question is more about extended range dives away from shore, i.e. toward the ocean or toward the middle of a lake.

I know the basics of burn time x .8 and switching between multiple scooters and related burn times for each, but when are you too far from shore? I'm sure the FL and West Coast guys can provide some info here.

Thanks

 

[PfcAJ]

You're too far when you can't make it back if something breaks. This is easily fixed by tow scooter(s).

That said, diving to the point where you need a tow scooter in open water seems absolutely ridiculous to me.

 

[ScubaInChicago]

You're too far when you can't make it back if something breaks. This is easily fixed by tow scooter(s).

That's about the point we're at, our target is approximately 6600' from shore or roughly 45 min on the trigger each way @ 150'/min. The scooters get 120 min of burn @ roughly 160'/min. 120 x .8= 96 min of usable burn time, enough to get there and back with reserve.

Gas planning is almost a no brainer at a max depth of about 35' to the sand. PADI tables credit 205 min before deco if the entire dive was done at 35' vs the gradual increase of depth to the target and standard min. deco back to shore.

We're still thinking a third tow scooter is a good idea, but at what point does it become a whole ordeal not worth the undertaking?

 

[TSandM]

I dunno about the .8 thing . . . but on any dive where I don't think I could, or really don't want to swim back, I dive thirds on scooter burn time. This is on the theory that one failed scooter, if we've kept thirds, will permit the other diver to tow the failed diver at least close enough that you can swim the rest of the way.

For a LOT of the dives I do with a scooter, the limiting factor is going to be hypothermia if our time in the water is overly prolonged -- so even if we can GET back, if we can't get back fast enough, we're still in trouble.

I use a Sierra with 60 minutes burn time on the battery; I will not go offshore more than 15 minutes.

 

[LiteHedded]

seems like a boat is the way to go...

 

[PfcAJ]

So thirds when you only have 1 scooter each doesn't make a lot of sense. It doesn't require 2x the power just to tow someone. Saving 20% in reserve makes sense for 1 scooter dives in order to not run down the batteries a lot and afford you a little extra to tow a diver. It really shouldn't slow you down much with a diver in the proper tow position. Fwiw, you might be risking melting a brushboard if you're on the trigger for 45mins, then turn right around and run for another 45mins. I wouldn't sign up for that on a dive where I needed the scooter to get home. Pitch it back, go a little slower, and save your motor.

But what REALLY doesn't make sense is scootering a mile out into open water. Take a boat. Way more DIR to take a boat than to risk a 6000ft scooter ride. Yes, divers often dive long distances in caves, but there is no other way to get to that spot in the cave other than to scooter there. If you CAN get there without the long scooter (via boat), do that.

 

[Errol Kalayci]

We often travel 3-5 miles in the ocean on dpv with a spare clipped off pulling a torpedo float with a boat following us. I would not do a shore dpv dive where I live or one without a boat, ever.

 

[rjack321]

So thirds when you only have 1 scooter each doesn't make a lot of sense. It doesn't require 2x the power just to tow someone. Saving 20% in reserve makes sense for 1 scooter dives in order to not run down the batteries a lot and afford you a little extra to tow a diver. It really shouldn't slow you down much with a diver in the proper tow position. Fwiw, you might be risking melting a brushboard if you're on the trigger for 45mins, then turn right around and run for another 45mins. I wouldn't sign up for that on a dive where I needed the scooter to get home. Pitch it back, go a little slower, and save your motor.
.

I can't believe this is an actual issue... Modernize to a brushless scooter where this whole "melting the brushboard" issue is moot.

We're still thinking a third tow scooter is a good idea, but at what point does it become a whole ordeal not worth the undertaking?

45mins each way is not really that big a deal. Based on the profile you described (35ft max depth), I'd be more concerned about boats, props and the lack of a dive flag than the scooters.

 

[PfcAJ]

I kinda thought he was talkin about Gavins with the reference to the burntimes (very Gavin-ish). But yeah, upgrade to a more modern scooter and that problem goes away.

 

[ScubaInChicago]

Here's a snippet of what we had planned with a visual reference for 3/4 of the trip. Our dive plan was to stay at depth the entire trip to avoid boat traffic (with 6' SMB's in case of an emergency). We were also thinking of using cave line from the break wall toward the wreck and using a gps deployed to the surface long enough to get a fix and reel it back down to fine tune our location. The scooters we're thinking of taking are Hollis H-160's which the most critical part would be to get us off the break wall and to the wreck (2000') and back.

For the record, I have two lifetime memberships on a charterboat that I could hit this wreck on any weekend. The point of the dive is to have fun doing something no one else has done, and maybe get others interested if it proves to be a routine type dive with some semi-permanent guideline laid.