Tunnel Hull or not?

[HoytHunter69]

new to jet boats. and I have a question. my first Jet was a 90/65 tunnel hull. I have just recently sold it and Im looking to upgrade. looking at a few on Bass Boat Central. looks like there are several guys that dont run tunnel hulls? I'm looking at an ALLWELD and a few others. do I need a tunnel or not? I would guess you can run a little more shallow with less worries but I want some of the experts opinions.Is it better or worse, or does it even make a difference? thanks in advance.

 

[catmansteve]

It seems to me that tunnels are somewhat of a regional thing, and also personal preference. They can help protect your jet foot if you run areas with lots of big rocks, with the drawbacks of drafting slightly shallower while drifting, as well as planing/porpoising/cavitation issues if not designed and set up properly. A lot of Eastern guys swear by them, a lot of Midwestern guys laugh at them... It's basically a Ford vs. Chevy or Merc. vs. OMC argument :shock:

 

[HoytHunter69]

It seems to me that tunnels are somewhat of a regional thing, and also personal preference. They can help protect your jet foot if you run areas with lots of big rocks, with the drawbacks of drafting slightly shallower while drifting, as well as planing/porpoising/cavitation issues if not designed and set up properly. A lot of Eastern guys swear by them, a lot of Midwestern guys laugh at them... It's basically a Ford vs. Chevy or Merc. vs. OMC argument :shock:

Thanks! the one I just got rid of had one and I just thought they all should? but like I said I'm looking at a few now that dont have a tunnel.

 

[Novicaine]

I've never owned a tunnel, but I am modifying my non-tunnel boat to have one (See my modification thread at https://www.tinboats.net/forum/viewtopic.php?f=21&t=24908 )

My reasoning is this:

My local river is not a clear see-thru "mountain spring" type of water. It is brown and nasty and muddy.

So when you're going along and the river gets too shallow (like 4" or less), you hit bottom before you know it. And since my jet intake was the lowest point of the boat, it would hit first and act like a scoop scooping rocks & sand through the jet, wearing out the impellor and wear ring, stuffing the engine full of sand, and lots of times, if large rocks were involved, damaging my jet intake.

So my theory is, lift the jet intake a couple inches above the rest of the boat ... this will give it a fighting chance of not having it's face rubbed through the sand. If it hurts top end speed or performance, I can live with that. I only need to go 10-20mph, usually as low as I can to stay on plane.

 

[HoytHunter69]

I've never owned a tunnel, but I am modifying my non-tunnel boat to have one (See my modification thread at https://www.tinboats.net/forum/viewtopic.php?f=21&t=24908 )

My reasoning is this:

My local river is not a clear see-thru "mountain spring" type of water. It is brown and nasty and muddy.

So when you're going along and the river gets too shallow (like 4" or less), you hit bottom before you know it. And since my jet intake was the lowest point of the boat, it would hit first and act like a scoop scooping rocks & sand through the jet, wearing out the impellor and wear ring, stuffing the engine full of sand, and lots of times, if large rocks were involved, damaging my jet intake.

So my theory is, lift the jet intake a couple inches above the rest of the boat ... this will give it a fighting chance of not having it's face rubbed through the sand. If it hurts top end speed or performance, I can live with that. I only need to go 10-20mph, usually as low as I can to stay on plane.

Thats pretty much the same way I was looking at it. I run shallow sandy rivers and I didnt wat to be scooping sand all the time. several times in my tunnel we would drag bottom or be on dry dirt for seconds. I know if that intake was just a little lower than my hull I would have been abusing it bad.

Thanks for the help!

 

[HoytHunter69]

I've never owned a tunnel, but I am modifying my non-tunnel boat to have one (See my modification thread at https://www.tinboats.net/forum/viewtopic.php?f=21&t=24908 )

My reasoning is this:

My local river is not a clear see-thru "mountain spring" type of water. It is brown and nasty and muddy.

So when you're going along and the river gets too shallow (like 4" or less), you hit bottom before you know it. And since my jet intake was the lowest point of the boat, it would hit first and act like a scoop scooping rocks & sand through the jet, wearing out the impellor and wear ring, stuffing the engine full of sand, and lots of times, if large rocks were involved, damaging my jet intake.

So my theory is, lift the jet intake a couple inches above the rest of the boat ... this will give it a fighting chance of not having it's face rubbed through the sand. If it hurts top end speed or performance, I can live with that. I only need to go 10-20mph, usually as low as I can to stay on plane.