shore landing and deep V

General boating discussion
Morning bite
Posts: 8
Joined: Mon Dec 30, 2019 10:17 am

shore landing and deep V

#1

Post by Morning bite »

Hello all,
I am planning on a build of the "perfect" boat for shore landing and salmon fishing in the ocean. I wonder about the higher dead rise and coming to shore to unload gear at a cabin. I appreciate peoples thoughts.

kmorin
Donator 08, 09, 10, 11, 12, 13, 14 15, 16 17, 18, 19, 20
Posts: 1487
Joined: Mon Aug 18, 2008 1:37 am
Location: Kenai, Alaska

Re: shore landing and deep V

#2

Post by kmorin »

AMbite,
I think you've hit on a topic that may go around boat owners as long as there are boats! Yes indeed, the trade off of entry vs beach landings!!

I'm sure you're aware of a few classic or maybe basic questions involved but for readers' sakes I'll mention them anyway.

How steep is the beach? Here in the Cook Inlet we have some beaches that are so flat a mere 1' of tidal depth will reveal 1/4 mile of beach!!! So no matter how flat bottomed a skiff- it will go dry a 1/2 mile offshore with the right load and state of the tide.

A deep V, on these beaches or others like them will go dry so far off shore you just "wait for the tide".

On other beaches, the bottom falls rapidly and you can bring a 50'er up and land dry without hitting bottom! So, this point is to try to encourage you to examine the beach's pitch/angle/slope to get some idea of what amount of tide will 'dry out' the beach?

Next is the age old "ride" question. Lots of builders and designers list the deadrise of the bottom at the stern/transom/aft most transverse section of the hull. So, if they list a 15 or 18 deg bottom (?) they're describing the angle of the bottom from the keel to the waterline (at rest) nearest the stern.

Usually, in single panel bottom hulls which make up 95% of the welded market designs, the forward sections of the bottom will be warped somewhat to a greater deadrise. This gives sharper entry when running into a head sea at planing speeds. But.... this design, of course, gives a deeper draft for any given cross section when landing!

So you've hit on the age old question; what is enough deadrise to give a soft (safe) ride at speed while still maintaining a "beachable" bow shape so I don't ground the keel at the forefoot before I get to the shore??

and the answer is: IT all depends. It depends on so many variables that you'd have to start making design decisions pretty soon! What is the all up displacement? LOA? Top Speed? MAX speed in four seastates (< 2' seas: < 4' seas: < 6' seas: <8' seas) if you need to go 3/4 throttle, say 30mph into a 6' sea (!!) ? for example.... the bottom of your hull's forefoot is going to have to be a very different sectional shape than if you only need to do 1/2 throttle (say 18mph) into a 4' sea!!!

Once you make some definite decisions regarding LOA, top end, and bow too speeds in various seas... you can being to compare those shapes' waterlines to the slope of your beach to realistically predict landing the hull.

Just food for thought. I've been around this part of the design helix a few times myself, and believe each designer will have some version of these types of questions he/she will ask you to decide before a hull's forefoot Profile and Section can be drawn.

Stock designs may be much less expensive that a new set of lines? They're known quantities and you may be able to find someone with a hull similar to your goal- to charter for a day's fishing and then some test landings at your cabin site? This would be less expensive, IMO, than starting with white paper and a criteria or two for your project?

Cheers,
Kevin Morin
Kenai, AK
kmorin

Morning bite
Posts: 8
Joined: Mon Dec 30, 2019 10:17 am

Re: shore landing and deep V

#3

Post by Morning bite »

Thanks for the great info. At high tide, it won't matter. At low tide it can be sketchy. I am looking at a 24 or 26 pacific with 18 inch dead rise. i am looking at others as well. I hope to have a boat I can fish most weather, but not the bad stuff, but also shore land to a cabin on an island.

kmorin
Donator 08, 09, 10, 11, 12, 13, 14 15, 16 17, 18, 19, 20
Posts: 1487
Joined: Mon Aug 18, 2008 1:37 am
Location: Kenai, Alaska

Re: shore landing and deep V

#4

Post by kmorin »

AMbite,
is that 18" of deadrise or 18 degrees? 18" would be a pretty steep bottom and likely to roll over on one chine and float from keel to chine instead of chine to chine with the keel down?

if the builder will help? finding existing boats, or owners who will consider giving you an on the water trial is likely to tell you more than any other way of learning about a hull's performance?

Cheers,
Kevin Morin
Kenai, AK
kmorin

Morning bite
Posts: 8
Joined: Mon Dec 30, 2019 10:17 am

Re: shore landing and deep V

#5

Post by Morning bite »

18 degree deadrise. draft of 12 inches. I am planning on trying to ride in one before I pull the trigger

kmorin
Donator 08, 09, 10, 11, 12, 13, 14 15, 16 17, 18, 19, 20
Posts: 1487
Joined: Mon Aug 18, 2008 1:37 am
Location: Kenai, Alaska

Re: shore landing and deep V

#6

Post by kmorin »

AM bite
that sounds more conventional- not sure of Pacific's deadrise angles but 18 deg sounds like something we've come to expect.

I think you're following a good path to see if you can organize a test ride/drive/outing before making a decision.

Cheers,
Kevin Morin
Kenai, AK
kmorin

Post Reply Previous topicNext topic