I have 2014 24 foot thunderjet. In Canada it model name is tyee. Its very steep rides and cuts even big chop and swells very well but has very shallow chine. If running on step and some happens to walk around I definitely know it and have to adjust trim tabs I see the newer models have a way wider chine now I’m wondering how much ride (cut). It loses to gain how much stability? And btw your raider boats are very nice really like you roof design will definitely be taking one out when it’s time for the next boat
My best friends son-in-law has an unlimited 100-ton Captains license, and he runs a charter boat company when he's not at sea. He owns a 30' North River offshore. He occasionally borrowed my 220 Profisherman for personal use. He always compared it to a sports car as it could turn on a dime while maintaining control. Hop up on step quickly with a single 200hp Honda. Personally, I've turned sharp enough at speed to appear to dip the rail. But I've never felt it slip in the turn.
The main purpose of a chine is to keep the boat from rocking at very slow speeds or at standstill. It can also add lift for easier planning. At least that's what the Naval Architecture Ship Design manual states. I have been in both styles of a boat in fact I own one (Northriver) with a fake chine (angle piece of metal). My friends boat (Weldcraft) has an actual chine and his boat does not rock as much as mine when walking from one side of the boat to the other. His boat seems more stable at the dock and a slow troll, but my boat rides way better through chop than his.
Great examples and you're exactly spot on about ship design. It most definitely increases stability at rest which is what we state in this video. A chine flat or a reverse chine is a mechanism for lift while underway and a mechanism for stability while at rest. On light weight boats (sub 10,000#) there is no need for a major chine flat. Stability is a primary focus but at what cost? Is the contrary unstable or is it just less stable? For instance, your friends boat, you would definitely say it is more stable but would you say your boat is not stable or is very tender? Everything is a trade off. To gain the stability, you sacrifice the ride just as you've experienced in your two examples. As for lift, our offshore bracket is a very different design than your boat has, it's full width and whereas its influence with stability at a static rest isn't worth mentioning, it gives us all the stern lift we ever need, your boat does that with the 1x2" angle welded to the chine extrusion. Nothing wrong with that but it's a way that can garner lift while underway but not at rest. If they add buoyancy to the stern like we have their bow would drop way deeper in the water particularly at low speeds which is very dangerous in rough water. So they decide to use that angle, and it works great. To add buoyancy in the stern, you must counter that in the bow.
Spot on. It adds stability to my sled but not much. Bottom width i wish had gotten wider model. Wish i had got an older hull without reverse chines now too. Going thru chop This is a small 17 foot sled that pounds more than a 30 year old tracker i also run. With that said the lift effects allowed me to run a 25hp on boat with r chines which is heavier thr tracker with same motor and being lighter did not plane as quick
That's the primary benefit to a chine flat. Where it suffers on smaller boats is when running into a head sea. The more sizable the head sea the worse it is. I learned designing boats, there are very few universal truths, it's all a give and take. That being said, we introduce reverse chines to larger boats where the weight of the vessel can overcome the added resistance upon entry into swells that a chine flat produces.
Don't chines also help with reducing the rate of splashback into the stern deck? We were in a raider on a albacore run last year where the crosswind was blowing our spray (which was going high due to lack of chines) right into the stern and the captain was judging if we should scrub based on how many minutes on and off the automatic bildge was runing. He was fine with 9 minutes on 1 minute off every 10 minute increment😅. Little nervewraking.
Depends on the wind scenario. A non chine flat boat will be wetter.. typically. Everything is a give and take and I've been on plenty of chine flatted boats that in a hard quartering that's windy got very wet, some also just had a lot of weight that punched through swells vs over them. There is a glass boat brand of big 30' offshore boats in a port I run out of. Lots of bow flare, big chine flats yet they run canvas curtains over the back of the cabin wall so people sitting just outside of the cabin don't get soaked . There is a lot more to that than just chine flats but it is a factor. Everything is a give and take. Whenever we make a change, we have to be improving something of higher value than we're creating.
bro....amazing control and that boat is amazing...Holy cow on the reverse chines. Knowledge is POWER....Incredible man
I have 2014 24 foot thunderjet. In Canada it model name is tyee. Its very steep rides and cuts even big chop and swells very well but has very shallow chine. If running on step and some happens to walk around I definitely know it and have to adjust trim tabs I see the newer models have a way wider chine now I’m wondering how much ride (cut). It loses to gain how much stability? And btw your raider boats are very nice really like you roof design will definitely be taking one out when it’s time for the next boat
My best friends son-in-law has an unlimited 100-ton Captains license, and he runs a charter boat company when he's not at sea. He owns a 30' North River offshore. He occasionally borrowed my 220 Profisherman for personal use. He always compared it to a sports car as it could turn on a dime while maintaining control. Hop up on step quickly with a single 200hp Honda. Personally, I've turned sharp enough at speed to appear to dip the rail. But I've never felt it slip in the turn.
The main purpose of a chine is to keep the boat from rocking at very slow speeds or at standstill. It can also add lift for easier planning. At least that's what the Naval Architecture Ship Design manual states. I have been in both styles of a boat in fact I own one (Northriver) with a fake chine (angle piece of metal). My friends boat (Weldcraft) has an actual chine and his boat does not rock as much as mine when walking from one side of the boat to the other. His boat seems more stable at the dock and a slow troll, but my boat rides way better through chop than his.
Great examples and you're exactly spot on about ship design. It most definitely increases stability at rest which is what we state in this video. A chine flat or a reverse chine is a mechanism for lift while underway and a mechanism for stability while at rest. On light weight boats (sub 10,000#) there is no need for a major chine flat. Stability is a primary focus but at what cost? Is the contrary unstable or is it just less stable? For instance, your friends boat, you would definitely say it is more stable but would you say your boat is not stable or is very tender? Everything is a trade off. To gain the stability, you sacrifice the ride just as you've experienced in your two examples.
As for lift, our offshore bracket is a very different design than your boat has, it's full width and whereas its influence with stability at a static rest isn't worth mentioning, it gives us all the stern lift we ever need, your boat does that with the 1x2" angle welded to the chine extrusion. Nothing wrong with that but it's a way that can garner lift while underway but not at rest. If they add buoyancy to the stern like we have their bow would drop way deeper in the water particularly at low speeds which is very dangerous in rough water. So they decide to use that angle, and it works great. To add buoyancy in the stern, you must counter that in the bow.
What boat model is in the video?
2584 Coastal w/ a 300 Suzuki
Spot on. It adds stability to my sled but not much. Bottom width i wish had gotten wider model. Wish i had got an older hull without reverse chines now too. Going thru chop
This is a small 17 foot sled that pounds more than a 30 year old tracker i also run. With that said the lift effects allowed me to run a 25hp on boat with r chines which is heavier thr tracker with same motor and being lighter did not plane as quick
Nice discussion. I’ve fished on larger boats with reverse chines. On the drift, I’ve noticed they provide a small amount of stability.
That's the primary benefit to a chine flat. Where it suffers on smaller boats is when running into a head sea. The more sizable the head sea the worse it is. I learned designing boats, there are very few universal truths, it's all a give and take. That being said, we introduce reverse chines to larger boats where the weight of the vessel can overcome the added resistance upon entry into swells that a chine flat produces.
Don't chines also help with reducing the rate of splashback into the stern deck? We were in a raider on a albacore run last year where the crosswind was blowing our spray (which was going high due to lack of chines) right into the stern and the captain was judging if we should scrub based on how many minutes on and off the automatic bildge was runing. He was fine with 9 minutes on 1 minute off every 10 minute increment😅. Little nervewraking.
Depends on the wind scenario. A non chine flat boat will be wetter.. typically. Everything is a give and take and I've been on plenty of chine flatted boats that in a hard quartering that's windy got very wet, some also just had a lot of weight that punched through swells vs over them. There is a glass boat brand of big 30' offshore boats in a port I run out of. Lots of bow flare, big chine flats yet they run canvas curtains over the back of the cabin wall so people sitting just outside of the cabin don't get soaked . There is a lot more to that than just chine flats but it is a factor. Everything is a give and take. Whenever we make a change, we have to be improving something of higher value than we're creating.
Good video.
I appreciate the candid comments on the video and in the comments below , helps me understand this issue a lot better
So captain knowledge?!