how big a sea can my boat handle?

Tad--you seem to be able to read my mind.

sadly it was because of my gut feelings on this that i have abandoned a flat bottom hull altogether-i love Mal..he has been so helpful-but i have had nagging doubts for using it on the great lakes...where the chop gets nasty...

so after my frames were competed--i cut them up and bought a set of glen-l's fred murphy plans--but cannot stand that the topsides are not plumb -hindering work duties

again the topsides are not plumb..as mentioned to you before in a previous thread..

for me a big flaw but it does keep the displacement down...and i can use my "toy" (as you put)36 hp engine geared 4.25:1 in it and still get 8.5 knots...and over 200 ft lbs of torque.! while using about 3/4 gals per hour running without a tow.

,..but since its not going to be used
much for work duties--only occasional light houseboat tows- it should make for a nice seaworthy tug--has nice accomodations for a 26 ft'er. very fair hull...

p.s.

-the feature that drew me to this boat was both the write up and I contacted Glen-l Witt to see what mr Witt had to say about it..--i asked him to compare it to coastal cruiser plans they sell of similar length he informed me it would handle just about anything within reason as far as seas much better than the coastal cruiser...


i also have a lead on a 4lw gardner- 62 hp @ 1500 rpms that might be a better small tug engine..and gear it 2:1--

thanks Tad--always a big help--id send you positive feedback again but the system wont let me...can i pm you on a couple easy questions?..or are you mega busy these days? thanks regadless...ive gotten a lot of info from you that has chnaged my ideas on things and your post today confirm my gut feelings...

see below for hydros on my own 26 ft design loosely based on the FM but with plum topsides...let me know if you need more info

see pics- the only confusion i have is the dif between center of floatation and center of bouyancy?..whats the diff?


Volume Displacement = 188.146
Center of Buoyancy = -1.64505, -0.316839, -0.62396
Wetted Surface Area = 224.348
Waterline Length = 24.3692
Maximum Waterline Beam = 9.99209
Water Plane Area = 191.263
Center of Floatation = 0.297725, -0.316402,0

the barge houseboat pictured is the intended tow occasionally - 10 ft beam rockered barge with scuppers.

 

your point - was most duly noted--good insight to bring up...

i guess thats why small boats have crew weight limits and engine weight limits?

 

All boats have crew weight limits and engine weight limits. You just run into them quicker on small boats. (And there is usually less margin for error, at least in absolute terms.)

 

Dstaal --thx for the post!
Doug

 

Center of Buoyancy is the center of all underwater volume, in this case three distances giving Longitudinal, Vertical, and Athwartships (X, Y, Z) centers.

Center of Floatation is the center of the waterplane area (around which the boat will trim), in this case a longitudinal distance and an athwartships distance(your hull is heeled).

As the boat changes trim CB and CF will move around independently, depending on hull shape.

Usually hydrostatics are set up as longitudinal distances from the bow or stern (or the midships station) and verticaly from a base (keel) line.

 

Hey Tug-from your lat/long looks like you are on Manitoulin-Lake Road,been there,nice place.
It seems you are looking to hang around Georgian Bay/Thousand Islands so going to be very sheltered.
Nice looking float home...

 

Thanks Westvanhan--yea--manitoulin is beautiful...well there are vast open stretches of shoreline...
like from meldrum bay to detroit /windsor etc...so the boat needs to be sea worthy--went to look at a gardner diesel today--what a mess..whoever had her really let her go--i almost cried..it was a 4lw...