Sister and Brother In-Law's Boat

[kmorin]

continuing on the family theme of welded aluminum boats, here are some shots of the my sister and brother-in-laws boat.

The boat began life as a set net skiff built by my brother-in-law but featuring poor financial dealings leading to his repossession of the boat.

Then it lived as a skiff camping boat for a few years and he decided to buy a large outboard to power up. When we found the cost of large outboards approached pickup trucks we called an old friend, who had sold me engines when I built full-time, and he had a new Merc I/O package of 115hp for less than 40% of the outboard- what's not to like?

We decided that I'd get the stern and he'd get the bow of the remodel of his skiff and that we'd not build the cabin until we both agreed.

The stern I decided would be fan tailed, generally, where the rounding would make her more seakindly in a following sea and find some added room to put the 4' long engine & I/O. She was 8' at the gunwale so the fantail made a 4' radius addition- just right.



I added the fantail (its cold formed not rolled or cone braked) to extend the hull for the outdrive and left pocket for the trim tabs because my brother in law is a fanatic fishing guy who hates tabs in his fishing gear.



The hull is very shallow and the ride is too hard for any real speed in a swell but inside the bay's and Prince William Sound, she runs well and is a nice day boat. I built a hydraulic anchor winch for the fold top compartment at the front of the trunk cabin and never could talk the skipper into letting me install it.

To this day he sky's his anchor with a buoy and rarely thinks about that winch buried somewhere in the garage.



She's fairly low slung in profile to keep her windage low and to help her proportions as skiffs in the 24 class often have too tall a house line and suffer in the looks department- well some do in our eyes.

Like all the family boats, we continually add subtract and experiment with different hardware and mounts to see what we can build that makes life easier.

Cheers,

[JETTYWOLF]

another unique one there...Damn man. Will ya stop it!













NOT.

[Bullshipper]

Interesting comment about rounded transoms being better in following seas. Never thought of it that way, but it makes perfect sense.

I have a feeling what is same ol same ol in your neck of the woods is brand new for us, and I for one am enjoying this new point of view.

[JETTYWOLF]

I was thinking 30 knots in reverse???????

Rounded Transom's for backing speed races.

[kmorin]

Bull & JettyWolf

when a skiff shape (transom ended boat less than 30') sits or rides the waves instead of planing over it, the hull shape helps govern how she moves.

Wide flat bottom skiffs for net handling give a stability to stand in a beam sea and have both hands free to handle a net but they're not good at high speeds. On the other hand they're much more comfortable than the deeper V when drifting free in a beam sea. I'm discussing roll here, not all motion, so the wide flat bottom which is very 'stiff' has less roll than the V shapes because of the relative depth of the two hulls.

Flam or topsides leaning outward (but curving inward very slightly as the section rises from chine to sheer) in the forward half of the hull lifts the bow and vectors water off the bow when the hull faces the swell. Flare, hollow section lines of the same area we most often see flam in a metal skiff's forward topsides, moves the water into even more horizontal vector than flam.

Now if the seas are overtaking the hull, that is she's sitting a drift and working lines over her stern, flat transoms slap, splash and slew her about depending on the speed of the seas traveling and the amount of stern to move (heave). In the same skiff with a rounded stern there is no slewing or slapping or heave to the hull from sea's overtaking the hull. The rounded or fantail shapes lift because they have much more flam, and they don't heave the boat to one side because there is no flat plane to the above waterline transom hull surface.

Just like flam in the forward topsides helps dry the boat when she runs head to a swell, a fantail's overhang and rounded transom surface help skiffs to be more comfortable and dry when they're fishing lines while drifting in a swell coming from astern.

Besides a almost everyone likes a nice rounded stern - don't they?

cheers,

[Chaps]

Yup, they're just pretty. Most sport boats are never moving slow enough in a beam sea to warrant the work it takes to build them and the loss of cockpit space is also a negative but they certainly are shippy.

For many years a very popular builder up here (Calkins) produced a boat called the Bartender that was unequaled in its ability to safely make its way through our nasty inlets and effortlessly troll for salmon in beam seas. There have been a few homebuilt in aluminum.

[kmorin]

Chaps,

I think everyone on the West coast has heard of the Bartender and they do have a fine salty sheer and were/are double ended- but not fan tailed. Also the main difference in our sterns and the Bartender's double end- besides the stern having a stem line like a bow, is the bottom. This double end, just like a fantail, helps these boats to keep their heading in a following sea on the Oregon bars (Columbia River Entrance), hence the name of that design.

Because the bartender was originally made of wood/plywood a stepped bottom wasn't as practical, and besides Mr. Calkins didn't advocate them anyway- as far as I can find in his articles and notes. Our skiffs are T bottomed where the planing bottom doesn't run to the round shape of the transom surface; its "chopped off" (stepped) like a hydroplane's bottom- except in the center 1/4 of the bottom.

Not that we're running those speeds but the principal is to keep from 'dragging' the wake around the stern- a practice that is good at displacement speeds but not good at planing speeds. So we put a transition plate under these sterns to go from straight chine to chine line under water and rounded above.

The one drawback of the Bartender design was/is the "huge" amount of power needed to break these transom's clear of the water- to plane. They typically had a more power than the square transom designs of similar weight and build. To solve this Mr. Calkins cut off the double end of the design in a newer design called the Calkins Clipper which was almost the same boat- built in aluminum and had a squared off stern.

I worked on one, here in Alaska, over several years and various new ideas by the owner. The owner bought the boat with a 3208 Cat and a 10" (or 12" ?--- I don't recall) Hamilton Pump in it and combined with the slightly V'd bottom and light hull that boat ran 50+ MPH. However, low speed steering with jets in a swell wasn't very refined in the 80's so the owner bought two BMW diesel outdrive packages and we retrofitted the boat by adding to the hull's length and installing the two stern drives. The results were much better low speed steering and the same, or nearly the same, top end.

The hull was a bit narrow to float the Cat so she sat down by the stern until the pump was in use. The extension made the boat longer by 3' maybe 4' and added enough to her WL length to change the moment of her engines on her trim. The original boat was lighter than we'd expect to see in today's welded boats, demonstrating that we're usually building to heavier scantlings than absolutely necessary, but giving good reference to how long lasting today's 1/4" plate boats will last; forever.

As you mention, most times the planing hull is running before a sea and out running it but there are times when the following seas overtake and that's when different stern lines effect the hull's movements.

Cheers,