# To tunnel or not to tunnel?



## permitchaser (Aug 26, 2013)

Tunnels tend to squat when they run and they don't go as fast with the same power. They do go skinny though


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## Vertigo (Jun 3, 2012)

In my experience, a tunnel on a 14' hull is not tremendously effective. On bigger boats a tunnel will allow running on plane maybe 4" to 6" shallower than a conventional hull. A tunnel will not give a hole shot in shallower water than a conventional hull, and in some cases might need deeper water (for a good hole shot, it's the depth of the prop that matters, and at rest, a tunnel won't make your prop be any deeper). A tunnel will be slower and burn more gas. To take advantage of a tunnel you'll need a jack plate and a low dead-rise or flat bottomed hull. Flat bottomed hulls don't pole too well.

Tunnels are good if you need to run some distance in in water less than a foot deep, or if there are a lots of shallow cuts you need to run over to get to the fish. If the only times you get into shallows is on the trolling motor or poling, then you don't need a tunnel.

For reference, I currently own two tunnel hull boats and have owned about a dozen others in the past. I'm not anti-tunnel, but I wouldn't have one on a boat if I didn't absolutely need one for the areas I fish.


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## el9surf (Dec 23, 2008)

Unless you are running long distances like the Texas mud flats I don't really see an advantage to a tunnnel. They draft more, are harder to prop, and typically don't handle as well.
If you found a boat in your price range that fit everything you wanted and it happened to have a tunnel then I would ne willing to look past that. I won't ever go out of my way to own another tunnel boat for the reasons mentioned above.


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## devrep (Feb 22, 2009)

love my tunnel. run with my prop just slightly above the bottom of the boat, can run with it several inches higher if I need to but it can blow out in sharp turns. Can still float in very shallow water and can get on plane in a foot if I just gradually increase speed until on plane. To achieve this I use a PT SWC4 prop and a Shawing capture plate. Vengeance prop is useless with a tunnel hull. In the rocky area I fish it is very comforting to know your prop is not hanging below the hull.


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## permitchaser (Aug 26, 2013)

My big fat flats boat will run in 1.5 ft with the motor jacked up.


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## tj14 (Sep 8, 2013)

Nothing against the tunnel but its really tough to get a good prop for the 15-20hp class you would probably run with the SM tunnel. None of the prop guys take the low HP stuff seriously from my experience. If anyone has a good prop guy that works on the small props, please post!


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## Viking1 (May 23, 2010)

In Jacksonville we don't have a prop shop so I sent mine to General Propeller in Tampa. I typed up a note that I stuck in the hub that gave the type and length of the boat, the type and HP of my motor, the total weight for boat, motor, people and gear. From this they reconditioned my prop and it has worked great! I have a Gheenoe LT25 with a tunnel and I would agree with what others have said about a tunnel but one thing that I really like that was not mentioned about the tunnel is that with a Gheenoe it really helps keep the boat on track when poling. Here is another link that has some more options on prop repair http://www.customgheenoe.com/forum/viewtopic.php?f=23&t=27971


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## Matts (Sep 2, 2015)

Viking1 said:


> In Jacksonville we don't have a prop shop so I sent mine to General Propeller in Tampa. I typed up a note that I stuck in the hub that gave the type and length of the boat, the type and HP of my motor, the total weight for boat, motor, people and gear. From this they reconditioned my prop and it has worked great! I have a Gheenoe LT25 with a tunnel and I would agree with what others have said about a tunnel but one thing that I really like that was not mentioned about the tunnel is that with a Gheenoe it really helps keep the boat on track when poling. Here is another link that has some more options on prop repair http://www.customgheenoe.com/forum/viewtopic.php?f=23&t=27971


I'm not expert, but do own a tunnel. The big question, where and how will you fish? I fish all around the Upper Laguna Madre and prefer to sight fish so I routinely run in 6-7" of water and need to get up in 10-15". The other 90% of the people that live and fish here are perfectly fine with a boat that will run in 1.5-2' and get up in a little more. Many factors. For my fishing style, a tunnel, hydraulic jack plate and 4 blade prop are musts. 
Matt


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## devrep (Feb 22, 2009)

are you kidding? Ellis Propeller in Jax is the best prop shop I've ever used.


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## Viking1 (May 23, 2010)

No argument on that and also Jacksonville propeller was good but they are both out of business now.


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## AfterHours2 (Aug 2, 2010)

Viking1 said:


> In Jacksonville we don't have a prop shop so I sent mine to General Propeller in Tampa. I typed up a note that I stuck in the hub that gave the type and length of the boat, the type and HP of my motor, the total weight for boat, motor, people and gear. From this they reconditioned my prop and it has worked great! I have a Gheenoe LT25 with a tunnel and I would agree with what others have said about a tunnel but one thing that I really like that was not mentioned about the tunnel is that with a Gheenoe it really helps keep the boat on track when poling. Here is another link that has some more options on prop repair http://www.customgheenoe.com/forum/viewtopic.php?f=23&t=27971


Sorry to derail, but I have never seen a tunnel LT before. I gotta see some pics!


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## Nick (Sep 25, 2015)

AfterHours2 said:


> Sorry to derail, but I have never seen a tunnel LT before. I gotta see some pics!


Im 100% with Afterhours2, I wanna see that!


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## devrep (Feb 22, 2009)

Viking1 said:


> No argument on that and also Jacksonville propeller was good but they are both out of business now.


Wow didn't know that.


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## ratsix (Jul 2, 2014)

I have a larger boat than those mentioned - 17.8 Whipray 2002 and have taken full advantage of the tunnel to run out of some skinny skinny spots. I don't see any performance issues poling or running. I also fish out of a Whip 16 with a friend and can also compare to a newer Guide we fished out of. I would never give up my tunnel. Propping it was laborious for the previous owner who had the prop modified by Jack Foreman in Texas.


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## Viking1 (May 23, 2010)

Nick said:


> Im 100% with Afterhours2, I wanna see that!


I will start a new post so I don't derail.


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## jimsmicro (Oct 29, 2013)

In my area you stand a good chance of leaving your lower unit behind if you don't either run a jet or a tunnel. So many submerged logs, rocks, and oyster bars that will wreck your day. Also, it's the difference between running out of some spots and having to drift with the tide or idle for half an hour to deeper water. I don't burn grass flats but a lot of the areas I need to get in and out of are mud/sand/rock bottom for miles, or some areas I need to get into will be shallow on the rising tide and I want to get into deep creeks to take advantage of the low water. My tunnel allows me access to water most won't fish, or at least not until way after the tide comes in. I attribute a lot of my fishing success to being places nobody else is at...


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## Vertigo (Jun 3, 2012)

I've learned that I can't rely on a tunnel hull to protect my lower unit when running in extremely shallow water. There are always the random limestone rocks, stumps, and oyster bars that can remove a skeg or a prop or even a lower unit, even with the best of tunnel rigs. What does offer some protection is knowing the area, and knowing when to run and when to idle. A tunnel hull is a good tool, but needs to be used properly to be effective.

A few years ago I was fishing the back country and I noticed a brand new big-buck tunnel hull boat (no names, but it was a $50 K+ glass rig) a few hundred yards up the creek from me. The tide was going out. The novice skipper probably thought his tunnel made him invincible, and leaving his spot, he shot out of the hole and ran at high speed about 100 yards before he came to a grinding halt on an oyster bar. I idled over and tried to pull him off, but he was firmly grounded and the tide was still going out. I offered him a ride but he declined and ended up waiting about 8 hrs for the tide to come back in enough for him to get off the bar. Moral of the story: knowing where you're going is way more important than having a tunnel hull. I'm sure the fiberglass repair work cost him a bundle.


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## fjmaverick (Sep 18, 2015)

Rooster Tail

I own a tunnel and it does handle a lot different than other boats I have driven (but its not fair to compare a 17' tunnel to a offshore cc with 24 degrees of dead rise). I do find myself slowing down earlier that the boat tends to slide a little.


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## lowcountry88 (Sep 21, 2015)

fjmaverick said:


> Rooster Tail
> 
> I own a tunnel and it does handle a lot different than other boats I have driven (but its not fair to compare a 17' tunnel to a offshore cc with 24 degrees of dead rise). I do find myself slowing down earlier that the boat tends to slide a little.


 I had a saltmarsh tunnel 14'. It could run a crap trap line 3/4 the way out of the water. Dont think the tunnel added much draft if any. I ran a stock prop on a merc 25 on a mini jacker. The only cavitation problems i had were in a good chop.


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## Limp Shrimp (Aug 23, 2015)

Nick said:


> Im 100% with Afterhours2, I wanna see that!



http://www.customgheenoe.com/forum/viewtopic.php?t=6751


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## Whiskey Angler (Mar 20, 2015)

Limp Shrimp said:


> http://www.customgheenoe.com/forum/viewtopic.php?t=6751


Rad!


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## AfterHours2 (Aug 2, 2010)

Limp Shrimp said:


> http://www.customgheenoe.com/forum/viewtopic.php?t=6751


Holy Jacked Up!


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## Vertigo (Jun 3, 2012)

That gheenoe was for sale and apparently didn't have too many interested. I'm thinking that someone got way too carried away with modifications. A long shaft motor with a super extended jack plate, a tunnel that takes up about 1/3 of the planing area aft, trim tabs that are large enough to steer with. What were they thinking?


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## Viking1 (May 23, 2010)

Vertigo said:


> That gheenoe was for sale and apparently didn't have too many interested. I'm thinking that someone got way too carried away with modifications. A long shaft motor with a super extended jack plate, a tunnel that takes up about 1/3 of the planing area aft, trim tabs that are large enough to steer with. What were they thinking?


That is not my boat. The boat referenced was built for a special purpose, to see how shallow a Gheenoe can run. The test was done on a sand bank in the ML near JB's. Poles were driven into the sand and a plastic landscape divider was hung between the poles. The divider was raised after each pass of the boat going between the two poles at speed. The shallowest run that I saw was 3 3/4 inches. I will do my best to take some pictures and video of my Gheenoe that has a tunnel this weekend and post it up.


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## zlenart1 (May 26, 2013)

I have a salt marsh 14 with no tunnel and I wouldn't need or even want to run any shallower than this skiff already does on plane, but that's just my opinion. I fish mostly out of Goodland in the 10,000 islands if that helps


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## CurtisWright (May 9, 2012)

I have a big tunnel on my boat and in the mud it will run anywhere there is water. The best comparison I can think of is its like being in an all time 4wd vehicle. Every day fuel mileage and handling are not the best , but the 5% of the time when you need it is really worth it. When you get stuck though, your really stuck. Most tunnel boats run in several inches less than they float in.

I would only get a tunnel if you are running in mud. (Misissippi, Lousiana or Texas) The reason is that a tunnel keeps the water above the intake of the motor so you can run an outboard like a surface drive. The mud is soft enough for the bottom half of the motor and prop to cut through. If your on a sandy bottom the Skeg hits hard. Its not worth running that close so I would stick with the no tunnel version.

Another note on getting stuck. In the mud you cannot get out of the boat when grounded so its very advantageous to be able to stay on plane and skim off the mud flat you just drove up on. With Sand, you kind of want a non tunnel boat because the skeg hits the sand and tells you to stop well before your in trouble. On a Non Tunnel, the mud will not stop you until it clogs up the intake and the motor cuts off on a high temp alarm. Then your just there on a mudflat until high tide or someone with a long long rope comes by to pull you off. I've done this before, a wrong turn into a dead end lagoon in the Biloxi WMA, in a 162 Scout and belly crawling through the mud in 3" of water with your anchor rope in December really really sucks.

The Cure for tunnel "squat" is sponsons and reverse chines. The boat needs all the extra planning help and flotation lost from the tunnel. Lots of people are against sponsons, but they bring the COG forward. The boat pictured is registered as 16' but you have to view it like a 15' boat with built in extra flotating taps


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## Whiskey Angler (Mar 20, 2015)

Also, with regards to running super shallow through mud, just because you can doesn't mean you should. Depending on your outboard and its cooling design, you will be picking up and pumping small bits of shell through your cooling passages and thermostats. Here's a situation that sucks and I've dealt with many time on a big mercury outboard. Lower unit picks up shell, thermostats close with shell in them, water continues to flow through thermostats even when closed, and your engine will never heat up to correct operating temperatures. Only way to fix it, is to pull your thermostats, put them in boiling water, and clean all the little bits of oyster shell out....it sucks.


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## Viking1 (May 23, 2010)

Here is a link to my LT 25 Gheenoe with pictures and video of the tunnel.
http://www.microskiff.com/threads/gheenoe-lt-25-with-tunnel.36085/


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