Digger
06-25-2006, 09:05 AM
well instead of schoolwork the other day my mind drifted. Here is what I doodled
42’ runabout
prelim characteristics
LOA 42’ 6”
LWL 37’ 3”
Beam 8’ 0”
Disp ~12,000 lbs
Here’s a boat that blends a variety of characteristics to form a unique approach to a modern cruising runabout. The idea is to come up with a boat that would be fun to go from pt A to pt B in, with a good turn of speed, and then provide comfortable accommodations once there. By comfortable I mean all the usual amenities you would find in an express cruiser and in addition a true separate cabin for kids or guests. With todays fuel prices we don’t want to break the bank getting there, and this boat will let us prevent that.
This planing hull would have a fine entry with a good deadrise carried all the way aft. Just how much will depend on some subsequent performance analysis. For now, my thought for ideal power in this boat would be a single diesel, somewhere around 400 hp. Thru either a v-drive or I/O, this motor would be capable of pushing the boat to 35 kts at about 17 gph fuel consumption. This is pretty economical for a 42’ boat. Key to getting this speed out of modest power is keeping her weight down and keeping her skinny. 8 foot beam by todays standards is narrow. Back “in the day” say around 80 years ago this proportion would have been pretty normal. It was, and is, the easiest way to get speed out of a boat. But as the years went by engines got lighter and lighter and more powerful. Now all you have to do is cram more hp in a boat and you can make it as fast as you want, as fast as the wallet allows that is.
Her accommodations would consist of a v-berth all the way forward, big and wide enough for two consenting adults. Just aft to port would be a combination head/shower and aft of that a capable galley with fridge, microwave, sink, stove, and good storage. To starboard across from the head and galley would be a long settee placed behind a hi-lo convertible table. Up and aft through the companionway you find yourself in the cockpit styled like most go fasts of the day, with two comfortable bolsters and a bench seat behind. Aft of the cockpit over the raised hump you see in the profile would be a nice big sunpad. That hump is there because underneath, accessible thru the split rear bench seat in the cockpit, via a small two step companionway, is a two berth cabin. Perfect for kids or guests, and completely isolated from accommodations forward. Aft of that would be the engine room accessible thru the aft cabin or via overhead, outboard opening hatches.
There’s lots of “Donzi” in this designs styling. Beginning forward, her foredeck is pretty wide all the way forward, meaning her forward sections will have lots of flare reminiscent of the Hornet or St Tropez. Her raised cabin roofline, which will make for nice headroom in the main cabin, and curved windshield are a tribute to the 28’ Sportsman, one of my favorite boats of all time. When viewed from above in plan view, that raised roofline cue is carried aft behind the cockpit to form a base for the sunpad as well as provide more room in that snug little aft cabin. I drew in some tumblehome aft, which will complicate construction somewhat, but I think it looks great. As does her counter stern, reminiscent (to me anyway) of some of the bygone offshore racers like “Ghostrider”.
Of course, for the guy that just has to go fast, that can be accommodated. We could put in twin big blocks. They would have to be staggered because of her narrow beam aft, and that would mean losing the aft cabin. She could easily push high 70’s with moderate power. Fuel consumption would be around 80 gph at this speed, maybe a little more. So, $240/hr or $51/hr, your choice. Maybe she could have a “cruising” version with her single diesel and aft cabin, or a “racing” version with twin gas I/O’s.
42’ runabout
prelim characteristics
LOA 42’ 6”
LWL 37’ 3”
Beam 8’ 0”
Disp ~12,000 lbs
Here’s a boat that blends a variety of characteristics to form a unique approach to a modern cruising runabout. The idea is to come up with a boat that would be fun to go from pt A to pt B in, with a good turn of speed, and then provide comfortable accommodations once there. By comfortable I mean all the usual amenities you would find in an express cruiser and in addition a true separate cabin for kids or guests. With todays fuel prices we don’t want to break the bank getting there, and this boat will let us prevent that.
This planing hull would have a fine entry with a good deadrise carried all the way aft. Just how much will depend on some subsequent performance analysis. For now, my thought for ideal power in this boat would be a single diesel, somewhere around 400 hp. Thru either a v-drive or I/O, this motor would be capable of pushing the boat to 35 kts at about 17 gph fuel consumption. This is pretty economical for a 42’ boat. Key to getting this speed out of modest power is keeping her weight down and keeping her skinny. 8 foot beam by todays standards is narrow. Back “in the day” say around 80 years ago this proportion would have been pretty normal. It was, and is, the easiest way to get speed out of a boat. But as the years went by engines got lighter and lighter and more powerful. Now all you have to do is cram more hp in a boat and you can make it as fast as you want, as fast as the wallet allows that is.
Her accommodations would consist of a v-berth all the way forward, big and wide enough for two consenting adults. Just aft to port would be a combination head/shower and aft of that a capable galley with fridge, microwave, sink, stove, and good storage. To starboard across from the head and galley would be a long settee placed behind a hi-lo convertible table. Up and aft through the companionway you find yourself in the cockpit styled like most go fasts of the day, with two comfortable bolsters and a bench seat behind. Aft of the cockpit over the raised hump you see in the profile would be a nice big sunpad. That hump is there because underneath, accessible thru the split rear bench seat in the cockpit, via a small two step companionway, is a two berth cabin. Perfect for kids or guests, and completely isolated from accommodations forward. Aft of that would be the engine room accessible thru the aft cabin or via overhead, outboard opening hatches.
There’s lots of “Donzi” in this designs styling. Beginning forward, her foredeck is pretty wide all the way forward, meaning her forward sections will have lots of flare reminiscent of the Hornet or St Tropez. Her raised cabin roofline, which will make for nice headroom in the main cabin, and curved windshield are a tribute to the 28’ Sportsman, one of my favorite boats of all time. When viewed from above in plan view, that raised roofline cue is carried aft behind the cockpit to form a base for the sunpad as well as provide more room in that snug little aft cabin. I drew in some tumblehome aft, which will complicate construction somewhat, but I think it looks great. As does her counter stern, reminiscent (to me anyway) of some of the bygone offshore racers like “Ghostrider”.
Of course, for the guy that just has to go fast, that can be accommodated. We could put in twin big blocks. They would have to be staggered because of her narrow beam aft, and that would mean losing the aft cabin. She could easily push high 70’s with moderate power. Fuel consumption would be around 80 gph at this speed, maybe a little more. So, $240/hr or $51/hr, your choice. Maybe she could have a “cruising” version with her single diesel and aft cabin, or a “racing” version with twin gas I/O’s.