There is always a warranty that the ship shall pursue her proper course between the termini of the voyage insured, and therefore these termini should be distinctly stated in the policy. It is therefore one of the best established rules of insurance law, that the insurers are discharged by any deviation from the proper course of the voyage. Originally this term "deviation," * as employed in the law of insurance, had no wider mean ing; but now it is extended by the reason of the rule, to any material change in the risks assumed by the insurers. And the rule applies in full force, although the change does not increase the risk; for the insurers have a right to say that they assumed certain risks, and no other risks; (n) and the rule is, that any deviation whatever, not merely suspends the liability of the insurers, but discharges them from all future responsibility; but not for a loss caused before the deviation by a peril insured against. (o)

It may indeed be said, that the change of risk might be merely temporary, and that thereafter all subsequent risks are certainly and precisely just what they would have been had there been no deviation; and then the liability of the insurers might revive. There can, however, be few changes in the risks, if any, that leave all subsequent perils entirely and certainly unaffected. (p)

Usage has especial influence in determining what is the proper there is no implied warranty of seaworthiness in any case in a time policy of insurance. Small v. Gibson, 16 Q. B. 128, 141, 4 R L. Cas. 353; Jenkins v. Heycock, 8 Moore, P. C. 351; Michael v. Tredwin, 17 C B. 551; Thompson v. Hopper, 6 Ellis & B. 172, 937, Ellis, B. & E. 1028; Fawcus v. Sarsfleld, 6 Ellis & B. 192. In this country, after some discussion, the rule appears to be settled, that if the vessel is at sea at the time the risk commences, the only implied warranty is that the vessel was in existence as a vessel, but that if she is in port at the time of the inception of the risk there is an implied warranty that she shall be seaworthy when she leaves the port. See vessel should be seaworthy, Gibson v. Small, supplemented by Thompson v. Hopper and Fawcus v. Sarsfield, supra, being declared to have set at rest all controversies on this subject See Merchants' Ins. Co. v. Morrison, 62 Il. 242.

Hoxie v. Pacific Ins. Co. 7 Allen. 211; Macy v. Mut. Ins. Co. 12 Gray, 497; Capen v. Washington Ins. Co. 12 Cush. 517; Jones v. Ins. Co. 2 Wallace, C. C. 278; Rouse v. Ins. Co. 25 Law Rep. 528; Martin v. Fishing Ins. Co. 20 Pick. 389; Am. Ins. Co. v. Ogden, 20 Wend. 287; Hoxie v. Home Ins. Co. 82 Conn. 21.

(n) Maryland Ins. Co. v. Le Roy, 7 Cranch, 26; Child v. Sun Ins Co. 8 Sandf. 26; Kettell v. Wiggin, 13 Mass. 68; Hartly v. Buggin, 8 Doug. 39.

(o) Hare v. Travis, 7 B. & C. 14; Green v. Young, 2 Salk. 444; Richardson v. Maine Ins. Co. 6 Mass. 102.

(p) See Coffin v. Newburyport Ins. Co. 9 Mass. 449, per Sedgwick, J.

course for a voyage, and what is a departure from this course. (q) If there be no such usage, the master is always bound to proceed to his destination in that which is the best way, all things being considered. (r) At the same time, a master always must have from the nature of the case a certain amount of discretion; it is his duty to exercise his judgment; and the insured is bound to leave him at liberty to exercise his judgment. (s) There may certainly be a deviation before the * voyage begins, by unreasonable delay; (t)1 and such delay at an intermediate port would be a deviation. (u)

A deviation is always excused by a sufficient necessity; or rather a change of risk is not a deviation, which is caused and justified by a sufficient necessity. (v) This necessity must always be judged of by the circumstances, which, at the time, were presented for consideration to the assured or his master, and not by subsequent events. (w) 2

It must always be a voluntary act; for whatever is done under compulsion, (x) or indeed for any sufficient cause, is not a devia(q) Martin v. Delaware Ids. Co. 2 Wash. C. C. 254; Folsom v. Merchants Ins. Co. 38 Maine, 414; Bentaloe v. Pratt, J. B. Wallace, 58; Kettell v. Wiggin, 18 Mass. 68; Lockett v. Merch. Ins. Co. 10 Rob. La. 339; Mey v. South Carolina Ins. Co. 3 Brer. 829; Elliot v. Wilson, 4 Brown, P. C. 470; Vallance v. Dewer, 1 Camp. 503; Ougier v. Jennings, id. 505, note; Salvador v. Hopkins, 3 Burr. 1707; Gregory v. Christie, 3 Doug. 419; Depeyster v. Sun Ins. Co. 19 N. Y. 272.

(r) Martin v. Delaware Ins. Co. 2 Wash. C. C. 264; Brown v. Tayleur, 4 A. & E. 241.

(s) As where the master is required by usage, on reaching a certain point, to decide, on a consideration of the winds and currents, which of two or more routes is the best, and he without so deciding takes one of them in obedience to the sailing orders of his owners, this would be a deviation. Middlewood v. Blakes, 7 T. R. 162.

(t) Earl v. Shaw, 1 Johns. Cas. 313; Driscol v. Passmore, 1 B. & P. 200; Chitty v. Selwyn, 2 Atk. 359; Hull v.

Cooper, 14 East, 479; Hartley v. Buggin, 3 Doug. 89; Seamans v. Loring, 1 Mason, 127; Himely v. S. Car. Ins. Co. 8 Const. R. 154; Palmer v. Marshall, 8 Bing. 79; Mount v. Larkins, 8 Bing. 108. (u) Hamilton v. Sheddon, 8 M. & W. 49; Murden v. South Car. Ins. Co. 3 Const. R. 200; Coffin v. Newburyport Ins. Co. 9 Mass. 430; Williams v. Shee, tion; and what would otherwise be a deviation is not one, if a change of risk were made to avoid a peril of sufficient reality and magnitude, and was no greater than this cause required. (y) And as we have seen in the chapter on contracts of shipping, a change of the course of a ship is justified, if it were for the purpose of saving the life of persons on board another vessel. (z) l And we should apply the same rule to a deviation to save life on board the vessel insured, unless this deviation was made necessary by the want of sufficient means of cure on board; and this want might amount to unseaworthiness. (a)