Dry Tortugas

We have fuel flow meters and a gas use in gallons read out (Look like original SeaRay equipment). We have confirmed it to be accurate over time. The tank gauges are not. When they read near empty we still have 1/3 tank left. From half to full they seem to be good. You may want to run your boat until your gauges read empty them fill up to see what you really have. We go to Alaska and running on a gauge that says E is scary but knowing we have 1/4 tank left is good. We carry 25 gallons of gas on swim platform for the dinghy, that also make one feel happy.
 
Having done the west coast trip many times in different boats (I once ran a 23' Yamaha Jet boat to Key West)

From my records, the trip from Longboat Key to KW was 182nm.

If you have Garmins the best $160 I ever spent was on a GFS10 meter (I used it on my skiff) to determine fuel flow and range.

Might I suggest the following:
  • Sarasota to Palm Island Marina near Stump Pass (Aquamarine Palm Harbor now I think) - overnight and refuel. - about 30nm. You could also push further south and stay in Sanibel Island at 'Tween Waters.
  • Take ICW from Stump Pass to Key West. You will exit the ICW at Sanibel island. - about 140nm (less if you are in Sanibel)
  • KW to DT - about 42nm
 
We have not made it to DT yet - hopefully this will be the year.

Have made the trip on the west coast to the keys multiple times. Just never hit the right weather window.

Another staging option to consider is drop down the west coast, fueling at Marco island. Then straight shot down to Marathon. Over to Key West for a night and fuel. Stock Island is a good stop over. Eat at Hogfish, get some fuel then over to DT.

Not as much open water as going straight into KW. Just stay outside the Marco shoals leaving Marco island, then turn into Bullard bank. Follow the markers down to Marathon.

Just a thought...
 
Yes, was planning to embark Key West direct to DT and back. I don't see how I could do it any other way with a 320, even with an extra 30 gallons fuel stored someplace/somehow.

After these post replies, I am definitely going to do a dry run up and down the lower gulf coast to mimic the DT run and ensure I have my shit together on fuel requirement/optimization. Wasn't going to do that, but shame on me if I otherwise run out of fuel and weather goes to heck.

My math was very simple on my 320DA with inboards:

200 gal x 0.7MPG = 140 miles range

Some people might question 0.7MPG number as they might observe 0.8 - 0.9MPG. But those are very optimistic numbers and they cannot be used for such a long trip, out in the open on fully loaded boat. As soon as you add full gear, food, extra toys, fuel, water, go out in the open water and add some wind, current and seas.....I doubt you'll see anything high performance numbers.

I see that you have I/Os, so your numbers should be slightly better, but you have to keep your planning math on conservative side to avoid very unpleasant surprises. Also, depending on how long you planned on going, need to add generator usage. Even at 0.5GPH staying out there for several days, it all adds up rather quickly.

Also, don't overlook fresh water supply. Depending on the crew size, your 40gal FW tank might get empty much quicker than you think.
 
Regarding fuel I try to keep to the 1/4 rule where at any point in the trip I can turn around and be back with a minimum of 1/4 tank remaining. If I'm in what I call "big" water I like to increase that to 1/3 tank to account for difficult seas. I have made some calls like a 130 mile trip to the Bahamas from Cape Canaveral and finding out that Grand, my first stop, didn't have fuel. I ran the numbers and moved on to Spanish Cay but if they didn't have fuel I would have been hosed.... It was a very nervous trip at reduced speeds and in hind sight should have went south the 50 miles to West End.... Obviously you know your boat so I would recommend carrying enough fuel to ensure you will have the 1/3 when you return.
Tom
 
A general note as we are in Key West. Before anyone takes off running the ICW anywhere in the Southern part of Florida or East Coast ICW ya need to read closely the LNW (Local Notice to Mariners). The channels have moved a lot, some have almost totally disappeared and many many Aids to Navigation, (Markers) are gone, off station, leaning badly, broken off just below the water line waiting to snag your boat.

We came down from the Chesapeake Bay leaving there 12/2and arrived Stock Islsnd, KW 12/15. Lots of boats were off the channel following Markers/bouyes that might be 200 yards from where the channel was in shallow water. We traveled mid to high tide and kept abreast of the winds pushing water in or out of our route and fortunately had no problems. Most fixed mounted chart plotters are running in most cases 6 months to a couple of years old cards, data and so forth. In addition to our 7612 Garmin & E120 Ray Marine chart plotters which where current this past summer we run Navionics being updated daily on the Ipad sitting in the Ram mount on the bridge. We run Garmin Blue Chart which had Active Captain info on it but by now everyone should already know that info is not updated as it had been.

Be prepared and travel safely and get, keep as up to date data as you can. Navionics which also has crowd source sonar data being updated almost daily is what I currently find to be the most current data on the iPad chart plotter. Quite a few boats this fall got stuck in low water and I’m sure many heading north this spring will have the same results. I’m doing the best I can not to be one of them but he whom hasn’t run aground already in their life probably hasn’t traveled much.

Safe travels starts with good preplanning!
 
We have fuel flow meters and a gas use in gallons read out (Look like original SeaRay equipment). We have confirmed it to be accurate over time. The tank gauges are not. When they read near empty we still have 1/3 tank left. From half to full they seem to be good. You may want to run your boat until your gauges read empty them fill up to see what you really have. We go to Alaska and running on a gauge that says E is scary but knowing we have 1/4 tank left is good. We carry 25 gallons of gas on swim platform for the dinghy, that also make one feel happy.

Great info - didn't know about fuel flow meters/gas use...what a GREAT feature to have. Will do on running the tanks down near E and checking the fill. Have never let the tanks drop below 3/8. When I do a trial run down the gulf coast on the outside I will do so. Thanks.
 
Having done the west coast trip many times in different boats (I once ran a 23' Yamaha Jet boat to Key West)

From my records, the trip from Longboat Key to KW was 182nm.

If you have Garmins the best $160 I ever spent was on a GFS10 meter (I used it on my skiff) to determine fuel flow and range.

Might I suggest the following:
  • Sarasota to Palm Island Marina near Stump Pass (Aquamarine Palm Harbor now I think) - overnight and refuel. - about 30nm. You could also push further south and stay in Sanibel Island at 'Tween Waters.
  • Take ICW from Stump Pass to Key West. You will exit the ICW at Sanibel island. - about 140nm (less if you are in Sanibel)
  • KW to DT - about 42nm

Thanks K-9. I have the Garmin and will research the GFS10. The price is right for what that will do for long runs. Very helpful.

Because of a desire to spend a couple of nights on Marco Island, am going to do the Sarasota to Marco Island (mix of inside/outside) run, down to Marathon and onto KW. Then hope the weather gods are with us.
 
We have not made it to DT yet - hopefully this will be the year.

Have made the trip on the west coast to the keys multiple times. Just never hit the right weather window.

Another staging option to consider is drop down the west coast, fueling at Marco island. Then straight shot down to Marathon. Over to Key West for a night and fuel. Stock Island is a good stop over. Eat at Hogfish, get some fuel then over to DT.

Not as much open water as going straight into KW. Just stay outside the Marco shoals leaving Marco island, then turn into Bullard bank. Follow the markers down to Marathon.

Just a thought...

Will do exactly as you have advised. Was planning to stay at Marco Island for a couple of nights anyway, but have not boated south of there before. So, shoals and Bullard Bank noted. Thank you.
 
My math was very simple on my 320DA with inboards:

200 gal x 0.7MPG = 140 miles range

Some people might question 0.7MPG number as they might observe 0.8 - 0.9MPG. But those are very optimistic numbers and they cannot be used for such a long trip, out in the open on fully loaded boat. As soon as you add full gear, food, extra toys, fuel, water, go out in the open water and add some wind, current and seas.....I doubt you'll see anything high performance numbers.

I see that you have I/Os, so your numbers should be slightly better, but you have to keep your planning math on conservative side to avoid very unpleasant surprises. Also, depending on how long you planned on going, need to add generator usage. Even at 0.5GPH staying out there for several days, it all adds up rather quickly.

Also, don't overlook fresh water supply. Depending on the crew size, your 40gal FW tank might get empty much quicker than you think.

Alex - thanks for that. I have been looking for conservative MPG est. and have been hearing/reading .7 - 1.0 on the twin 6.2 merc I/O's, 25 MPH planed up. Definitely want the low side for calculations. I have come to the conclusion that its not a question of taking spare fuel on board, but how much. Am thinking 25-30 gallons. Genny use while in DT will default to fuel remaining after I get there. Thanks.
 
Regarding fuel I try to keep to the 1/4 rule where at any point in the trip I can turn around and be back with a minimum of 1/4 tank remaining. If I'm in what I call "big" water I like to increase that to 1/3 tank to account for difficult seas. I have made some calls like a 130 mile trip to the Bahamas from Cape Canaveral and finding out that Grand, my first stop, didn't have fuel. I ran the numbers and moved on to Spanish Cay but if they didn't have fuel I would have been hosed.... It was a very nervous trip at reduced speeds and in hind sight should have went south the 50 miles to West End.... Obviously you know your boat so I would recommend carrying enough fuel to ensure you will have the 1/3 when you return.
Tom

Thanks Tom - certainly good advice. I have not let my tanks drop below 3/8 before - regardless of never being further than 30 miles from a pump. So, I'll need to grow a pair for this trip. I think if I ran 145 NM with 200 gallons fuel, KW to DT and back at 25MPH in decent weather, I'd be at 1/8 at best, on fumes as a real possibility, and empty before I get back if life sucks that day. So, in addition to carrying extra fuel, will leave DT early morning and along the way I have the option to greatly reduce speed for MPG and add a few hours to the trip as a safety measure. It does seem to boil down the weather window each time I go through the planning. Will be prepared to stay on DT longer until I have the weather on my side. Also will be prepared to not leave KW if the 4 day forecast isn't what I need. Thank you.
 
What's the plan on how to check weather for the return trip after you are there?

No cell service.
 
It just may be a lot less pressure to leave your boat in a Key West Marina and take one of the two high speed ferries to the island and enjoy the ride. By the time you stress over loading, carrying and storing extra fuel on board, transferring it to your tanks and the potential of running out of it.....it may make more sense to order another Rum Runner and let someone else drive the boat.

https://www.drytortugas.com/rates-reservations/
 
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Also, I believe the correct distance between Key West and Dry Tortugas is 67 miles which on a good day means (your 140 range) you would need to carry 10-15 additional 5 gallon gas containers which weighs about 300-400 pounds on deck. A 50 gallon fuel bladder will set you back another $600.
 
Thanks Tom - certainly good advice. I have not let my tanks drop below 3/8 before - regardless of never being further than 30 miles from a pump. So, I'll need to grow a pair for this trip. I think if I ran 145 NM with 200 gallons fuel, KW to DT and back at 25MPH in decent weather, I'd be at 1/8 at best, on fumes as a real possibility, and empty before I get back if life sucks that day. So, in addition to carrying extra fuel, will leave DT early morning and along the way I have the option to greatly reduce speed for MPG and add a few hours to the trip as a safety measure. It does seem to boil down the weather window each time I go through the planning. Will be prepared to stay on DT longer until I have the weather on my side. Also will be prepared to not leave KW if the 4 day forecast isn't what I need. Thank you.
And here is another thought - Fueling in open water can be nearly impossible; five gallon tank, open fuel port on back of boat, hanging all out there, seas rolling and rocking the boat....... I can tell you it's not ideal. Consider a manual fuel pump so you can stay in the safety of the cockpit when transferring fuel.
 
Also, I believe the correct distance between Key West and Dry Tortugas is 67 miles which on a good day means (your 140 range) you would need to carry 10-15 additional 5 gallon gas containers which weighs about 300-400 pounds on deck.
 
I’d suggest you start an excel or numbers spread sheet as well as anyone else so you can calculate and track your tank capacity. What your gauge shows before you fill the tank or tanks, actual run hours, average RPMs run, compare gallons put in the tank to what she supposed to hold. You start tracking and calculating all this over four or five months with varying running conditions and you know pretty much spot on what to expect. Don’t forget to consider the current and wind average conditions along with sea state and then you should have something you can use for your boat, props, loading and running conditions. Doesn’t mean your buddies boat that might be the same on the outside will have your same numbers.

Example, our 52DB was over propped and great top speed. Took three changes to get the props dialed in where I wanted them along with real life loading conditions. Dropped 11gph consumption, now running at 80% RPMs, fully loaded fuel, water, 1/2 waste and all gear, 67-71% engine loading depending on sea conditions & windage. Cruising anywhere from 21-23nmk with EGT (exhaust gas temperatures) staying below 1,000 degrees at the turbo which is an important issue for QSM11’s manifolds, turbos & Engine life span.

Hope this adds some thoughts and ideas to improve your specific boat knowledge about your boat as it did my previous one and current one.

Safe travels, prethink all your proposed plans with the admirals thoughts in your mind as she will let you know more than ya want if ya miss calculate
 
What's the plan on how to check weather for the return trip after you are there?

No cell service.

Excellent question. I don't know if VHF WX broadcast is available in that area.

I can tell you that while cruising in the states where all (or most) services are available, we tend to take things for granted. As soon as you get to remote destinations with no service, what used to be simple becomes a real challenge.

Perhaps renting a satellite device like inReach Delorme with WX service is something consider. I own one and it's a great tool, which also allows you to stay connected being anywhere in the open water.

I know what goes through your head. You're looking to go to a secluded spot just for couple days and have to prep like you're about to cross the Atlantic. Unfortunately, it's kind of true just b/c you're reaching limitations of your rig, including communications. Obviously, it's all doable you just need to take some extra steps.

Travelling with a buddy boat is strongly recommended.
 
We have a sat phone. It works for data also but very slow. Try Global Star they may be less and the dealers rent them. They used to be 40 a month for unlimited voice and data when they were having satellite problems now they are 1,800 or so a year. Cell phones have replaced them in most coastal areas but in big water they can save your life. They cost less than a funeral or the lawyer probating your estate.
 

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